On 2016/11/07 11:24, Etsuro Fujita wrote:
On 2016/11/04 19:55, Etsuro Fujita wrote:
Attached is an updated version of the patch.
I noticed that I have included an unrelated regression test in the
patch. Attached is a patch with the test removed.
I noticed that I inadvertently removed some changes from that patch, so
I fixed that. Please find attached an updated version of the patch.
I'm also attaching an updated version of another patch for evaluating
PHVs remotely, which has been created on top of that patch. Changes to
the latter: I revised comments and added a bit more regression tests.
Best regards,
Etsuro Fujita
*** a/contrib/postgres_fdw/deparse.c
--- b/contrib/postgres_fdw/deparse.c
***************
*** 109,114 **** typedef struct deparse_expr_cxt
--- 109,116 ----
/* Handy macro to add relation name qualification */
#define ADD_REL_QUALIFIER(buf, varno) \
appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
+ #define SS_TAB_ALIAS_PREFIX "s"
+ #define SS_COL_ALIAS_PREFIX "c"
/*
* Functions to determine whether an expression can be evaluated safely on
***************
*** 167,172 **** static void appendConditions(List *exprs, deparse_expr_cxt *context);
--- 169,180 ----
static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
RelOptInfo *joinrel, bool use_alias, List **params_list);
static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
+ static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
+ bool make_subquery, List **params_list);
+ static void appendSubselectAlias(StringInfo buf, int tabno, int ncols);
+ static void getSubselectAliasInfo(Var *node, RelOptInfo *foreignrel,
+ int *tabno, int *colno);
+ static bool isSubqueryExpr(Var *node, RelOptInfo *foreignrel, int *tabno, int *colno);
static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
static void appendAggOrderBy(List *orderList, List *targetList,
***************
*** 990,999 **** deparseSelectSql(List *tlist, List **retrieved_attrs, deparse_expr_cxt *context)
*/
appendStringInfoString(buf, "SELECT ");
if (foreignrel->reloptkind == RELOPT_JOINREL ||
! foreignrel->reloptkind == RELOPT_UPPER_REL)
{
! /* For a join relation use the input tlist */
deparseExplicitTargetList(tlist, retrieved_attrs, context);
}
else
--- 998,1013 ----
*/
appendStringInfoString(buf, "SELECT ");
+ /*
+ * Note: non-NIL tlist might be supplied for a baserel; if the baserel is
+ * deparsed as a subquery, non-NIL tlist will be supplied for the baserel.
+ * (See deparseRangeTblRef.) In that case use deparseExplicitTargetList.
+ */
if (foreignrel->reloptkind == RELOPT_JOINREL ||
! foreignrel->reloptkind == RELOPT_UPPER_REL ||
! tlist != NIL)
{
! /* Use the input tlist */
deparseExplicitTargetList(tlist, retrieved_attrs, context);
}
else
***************
*** 1155,1165 **** deparseLockingClause(deparse_expr_cxt *context)
--- 1169,1188 ----
StringInfo buf = context->buf;
PlannerInfo *root = context->root;
RelOptInfo *rel = context->scanrel;
+ PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
int relid = -1;
while ((relid = bms_next_member(rel->relids, relid)) >= 0)
{
/*
+ * Ignore relation if it appears in a lower subquery, because in that
+ * case we would have already considered locking for the relation
+ * while deparsing the lower subquery.
+ */
+ if (bms_is_member(relid, fpinfo->subquery_rels))
+ continue;
+
+ /*
* Add FOR UPDATE/SHARE if appropriate. We apply locking during the
* initial row fetch, rather than later on as is done for local
* tables. The extra roundtrips involved in trying to duplicate the
***************
*** 1347,1364 **** deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
if (foreignrel->reloptkind == RELOPT_JOINREL)
{
- RelOptInfo *rel_o = fpinfo->outerrel;
- RelOptInfo *rel_i = fpinfo->innerrel;
StringInfoData join_sql_o;
StringInfoData join_sql_i;
/* Deparse outer relation */
initStringInfo(&join_sql_o);
! deparseFromExprForRel(&join_sql_o, root, rel_o, true, params_list);
/* Deparse inner relation */
initStringInfo(&join_sql_i);
! deparseFromExprForRel(&join_sql_i, root, rel_i, true, params_list);
/*
* For a join relation FROM clause entry is deparsed as
--- 1370,1391 ----
if (foreignrel->reloptkind == RELOPT_JOINREL)
{
StringInfoData join_sql_o;
StringInfoData join_sql_i;
/* Deparse outer relation */
initStringInfo(&join_sql_o);
! deparseRangeTblRef(&join_sql_o, root,
! fpinfo->outerrel,
! fpinfo->make_outerrel_subquery,
! params_list);
/* Deparse inner relation */
initStringInfo(&join_sql_i);
! deparseRangeTblRef(&join_sql_i, root,
! fpinfo->innerrel,
! fpinfo->make_innerrel_subquery,
! params_list);
/*
* For a join relation FROM clause entry is deparsed as
***************
*** 1414,1419 **** deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
--- 1441,1591 ----
}
/*
+ * Append operand relation of foreign join to buf.
+ */
+ static void
+ deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
+ bool make_subquery, List **params_list)
+ {
+ PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
+
+ Assert(foreignrel->reloptkind == RELOPT_BASEREL ||
+ foreignrel->reloptkind == RELOPT_JOINREL);
+ Assert(fpinfo->local_conds == NIL);
+
+ if (make_subquery)
+ {
+ List *tlist;
+ List *retrieved_attrs;
+
+ tlist = make_tlist_from_pathtarget(foreignrel->reltarget);
+ Assert(tlist != NIL);
+ appendStringInfoChar(buf, '(');
+ deparseSelectStmtForRel(buf, root, foreignrel, tlist,
+ fpinfo->remote_conds, NIL,
+ &retrieved_attrs, params_list);
+ appendStringInfoChar(buf, ')');
+ appendSubselectAlias(buf, fpinfo->relation_index,
+ list_length(foreignrel->reltarget->exprs));
+ }
+ else
+ deparseFromExprForRel(buf, root, foreignrel, true, params_list);
+ }
+
+ /*
+ * Add a subselect alias to a subquery-in-FROM.
+ *
+ * The table alias and column aliases are appended to buf. tabno is the index
+ * for the table alias, and ncols is the number of the column aliases to add.
+ * (The indexes for the column aliases are 1..ncols.)
+ */
+ static void
+ appendSubselectAlias(StringInfo buf, int tabno, int ncols)
+ {
+ int i;
+
+ /* Append the table alias */
+ appendStringInfo(buf, " %s%d", SS_TAB_ALIAS_PREFIX, tabno);
+
+ /* Append the column aliases */
+ appendStringInfoChar(buf, '(');
+ for (i = 1; i <= ncols; i++)
+ {
+ if (i > 1)
+ appendStringInfoString(buf, ", ");
+
+ appendStringInfo(buf, "%s%d", SS_COL_ALIAS_PREFIX, i);
+ }
+ appendStringInfoChar(buf, ')');
+ }
+
+ /*
+ * Get info about the subselect alias to given expression.
+ *
+ * The subselect table and column numbers are returned to *tabno and *colno,
+ * respectively.
+ */
+ static void
+ getSubselectAliasInfo(Var *node, RelOptInfo *foreignrel,
+ int *tabno, int *colno)
+ {
+ PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
+ int i;
+ ListCell *lc;
+
+ /* Get the table number */
+ *tabno = fpinfo->relation_index;
+
+ /* Get the column number */
+ i = 1;
+ foreach(lc, foreignrel->reltarget->exprs)
+ {
+ if (equal(lfirst(lc), (Node *) node))
+ {
+ *colno = i;
+ return;
+ }
+ i++;
+ }
+
+ /* Shouldn't get here */
+ elog(ERROR, "unexpected expression in subquery output");
+ }
+
+ /*
+ * Returns true if given expression is an output column of a subquery-in-FROM.
+ *
+ * The subselect table and column numbers are returned to *tabno and *colno,
+ * respectively, in that case.
+ */
+ static bool
+ isSubqueryExpr(Var *node, RelOptInfo *foreignrel, int *tabno, int *colno)
+ {
+ PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
+ RelOptInfo *outerrel = fpinfo->outerrel;
+ RelOptInfo *innerrel = fpinfo->innerrel;
+
+ if (foreignrel->reloptkind != RELOPT_JOINREL)
+ return false;
+
+ if (!fpinfo->subquery_rels)
+ return false;
+
+ if (bms_is_member(node->varno, outerrel->relids))
+ {
+ /*
+ * If outer relation is deparsed as a subqeury, the given expression
+ * will be an output column of the subquery; get the subselect alias
+ * info for the given expression.
+ */
+ if (fpinfo->make_outerrel_subquery)
+ {
+ getSubselectAliasInfo(node, outerrel, tabno, colno);
+ return true;
+ }
+ /* Otherwise, recurse into outer relation */
+ if (isSubqueryExpr(node, outerrel, tabno, colno))
+ return true;
+ }
+ else
+ {
+ Assert(bms_is_member(node->varno, innerrel->relids));
+
+ /*
+ * Likewise for inner relation
+ */
+ if (fpinfo->make_innerrel_subquery)
+ {
+ getSubselectAliasInfo(node, innerrel, tabno, colno);
+ return true;
+ }
+ if (isSubqueryExpr(node, innerrel, tabno, colno))
+ return true;
+ }
+ return false;
+ }
+
+ /*
* deparse remote INSERT statement
*
* The statement text is appended to buf, and we also create an integer List
***************
*** 2057,2066 **** static void
--- 2229,2254 ----
deparseVar(Var *node, deparse_expr_cxt *context)
{
Relids relids = context->scanrel->relids;
+ RelOptInfo *rel = (context->foreignrel->reloptkind == RELOPT_UPPER_REL) ?
+ context->scanrel : context->foreignrel;
+ int tabno;
+ int colno;
/* Qualify columns when multiple relations are involved. */
bool qualify_col = (bms_num_members(relids) > 1);
+ /*
+ * If the given Var is an output column of a subquery-in-FROM, deparse
+ * the alias to the given Var instead.
+ */
+ if (isSubqueryExpr(node, rel, &tabno, &colno))
+ {
+ appendStringInfo(context->buf, "%s%d.%s%d",
+ SS_TAB_ALIAS_PREFIX, tabno,
+ SS_COL_ALIAS_PREFIX, colno);
+ return;
+ }
+
if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
deparseColumnRef(context->buf, node->varno, node->varattno,
context->root, qualify_col);
*** a/contrib/postgres_fdw/expected/postgres_fdw.out
--- b/contrib/postgres_fdw/expected/postgres_fdw.out
***************
*** 1217,1241 **** SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.
(10 rows)
-- full outer join with restrictions on the joining relations
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1;
! QUERY PLAN
! ------------------------------------------------------------------------------------------------
! Sort
Output: ft4.c1, ft5.c1
! Sort Key: ft4.c1, ft5.c1
! -> Hash Full Join
! Output: ft4.c1, ft5.c1
! Hash Cond: (ft4.c1 = ft5.c1)
! -> Foreign Scan on public.ft4
! Output: ft4.c1, ft4.c2, ft4.c3
! Remote SQL: SELECT c1 FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))
! -> Hash
! Output: ft5.c1
! -> Foreign Scan on public.ft5
! Output: ft5.c1
! Remote SQL: SELECT c1 FROM "S 1"."T 4" WHERE ((c1 >= 50)) AND ((c1 <= 60))
! (14 rows)
SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1;
c1 | c1
--- 1217,1232 ----
(10 rows)
-- full outer join with restrictions on the joining relations
+ -- a. the joining relations are both base relations
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1;
! QUERY PLAN
! -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
! Foreign Scan
Output: ft4.c1, ft5.c1
! Relations: (public.ft4) FULL JOIN (public.ft5)
! Remote SQL: SELECT s4.c1, s5.c1 FROM ((SELECT c1 FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s4(c1) FULL JOIN (SELECT c1 FROM "S 1"."T 4" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s5(c1) ON (((s4.c1 = s5.c1)))) ORDER BY s4.c1 ASC NULLS LAST, s5.c1 ASC NULLS LAST
! (4 rows)
SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1;
c1 | c1
***************
*** 1250,1255 **** SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL
--- 1241,1293 ----
| 57
(8 rows)
+ -- b. one of the joining relations is a base relation and the other is a join
+ -- relation
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM ft4 t2 LEFT JOIN ft5 t3 ON (t2.c1 = t3.c1) WHERE (t2.c1 between 50 and 60)) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
+ QUERY PLAN
+ -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: ft4.c1, t2.c1, t3.c1
+ Relations: (public.ft4) FULL JOIN ((public.ft4 t2) LEFT JOIN (public.ft5 t3))
+ Remote SQL: SELECT s4.c1, s8.c1, s8.c2 FROM ((SELECT c1 FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s4(c1) FULL JOIN (SELECT r5.c1, r6.c1 FROM ("S 1"."T 3" r5 LEFT JOIN "S 1"."T 4" r6 ON (((r5.c1 = r6.c1)))) WHERE ((r5.c1 >= 50)) AND ((r5.c1 <= 60))) s8(c1, c2) ON (((s4.c1 = s8.c1)))) ORDER BY s4.c1 ASC NULLS LAST, s8.c1 ASC NULLS LAST, s8.c2 ASC NULLS LAST
+ (4 rows)
+
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM ft4 t2 LEFT JOIN ft5 t3 ON (t2.c1 = t3.c1) WHERE (t2.c1 between 50 and 60)) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
+ c1 | a | b
+ ----+----+----
+ 50 | 50 |
+ 52 | 52 |
+ 54 | 54 | 54
+ 56 | 56 |
+ 58 | 58 |
+ 60 | 60 | 60
+ (6 rows)
+
+ -- c. test deparsing the remote query as nested subqueries
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t2 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t3 ON (t2.c1 = t3.c1) WHERE t2.c1 IS NULL OR t2.c1 IS NOT NULL) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
+ QUERY PLAN
+ --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: ft4.c1, ft4_1.c1, ft5.c1
+ Relations: (public.ft4) FULL JOIN ((public.ft4) FULL JOIN (public.ft5))
+ Remote SQL: SELECT s4.c1, s10.c1, s10.c2 FROM ((SELECT c1 FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s4(c1) FULL JOIN (SELECT s8.c1, s9.c1 FROM ((SELECT c1 FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s8(c1) FULL JOIN (SELECT c1 FROM "S 1"."T 4" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s9(c1) ON (((s8.c1 = s9.c1)))) WHERE (((s8.c1 IS NULL) OR (s8.c1 IS NOT NULL)))) s10(c1, c2) ON (((s4.c1 = s10.c1)))) ORDER BY s4.c1 ASC NULLS LAST, s10.c1 ASC NULLS LAST, s10.c2 ASC NULLS LAST
+ (4 rows)
+
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t2 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t3 ON (t2.c1 = t3.c1) WHERE t2.c1 IS NULL OR t2.c1 IS NOT NULL) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
+ c1 | a | b
+ ----+----+----
+ 50 | 50 |
+ 52 | 52 |
+ 54 | 54 | 54
+ 56 | 56 |
+ 58 | 58 |
+ 60 | 60 | 60
+ | | 51
+ | | 57
+ (8 rows)
+
-- full outer join + inner join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1, t3.c1 FROM ft4 t1 INNER JOIN ft5 t2 ON (t1.c1 = t2.c1 + 1 and t1.c1 between 50 and 60) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) ORDER BY t1.c1, t2.c1, t3.c1 LIMIT 10;
***************
*** 3062,3067 **** select avg(t1.c1), sum(t2.c1) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) gr
--- 3100,3123 ----
| 9
(3 rows)
+ -- Aggregate over FULL join needing to deparse the joining relations as
+ -- subqueries.
+ explain (verbose, costs off)
+ select count(*), sum(t1.c1), avg(t2.c1) from (select c1 from ft4 where c1 between 50 and 60) t1 full join (select c1 from ft5 where c1 between 50 and 60) t2 on (t1.c1 = t2.c1);
+ QUERY PLAN
+ -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: (count(*)), (sum(ft4.c1)), (avg(ft5.c1))
+ Relations: Aggregate on ((public.ft4) FULL JOIN (public.ft5))
+ Remote SQL: SELECT count(*), sum(s4.c1), avg(s5.c1) FROM ((SELECT c1 FROM "S 1"."T 3" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s4(c1) FULL JOIN (SELECT c1 FROM "S 1"."T 4" WHERE ((c1 >= 50)) AND ((c1 <= 60))) s5(c1) ON (((s4.c1 = s5.c1))))
+ (4 rows)
+
+ select count(*), sum(t1.c1), avg(t2.c1) from (select c1 from ft4 where c1 between 50 and 60) t1 full join (select c1 from ft5 where c1 between 50 and 60) t2 on (t1.c1 = t2.c1);
+ count | sum | avg
+ -------+-----+---------------------
+ 8 | 330 | 55.5000000000000000
+ (1 row)
+
-- ORDER BY expression is part of the target list but not pushed down to
-- foreign server.
explain (verbose, costs off)
*** a/contrib/postgres_fdw/postgres_fdw.c
--- b/contrib/postgres_fdw/postgres_fdw.c
***************
*** 668,673 **** postgresGetForeignRelSize(PlannerInfo *root,
--- 668,681 ----
if (*refname && strcmp(refname, relname) != 0)
appendStringInfo(fpinfo->relation_name, " %s",
quote_identifier(rte->eref->aliasname));
+
+ /* Set the subquery information */
+ fpinfo->make_outerrel_subquery = false;
+ fpinfo->make_innerrel_subquery = false;
+ fpinfo->subquery_rels = NULL;
+
+ /* Set the relation index */
+ fpinfo->relation_index = baserel->relid;
}
/*
***************
*** 4147,4156 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
fpinfo->jointype = jointype;
/*
* Pull the other remote conditions from the joining relations into join
* clauses or other remote clauses (remote_conds) of this relation
! * wherever possible. This avoids building subqueries at every join step,
! * which is not currently supported by the deparser logic.
*
* For an inner join, clauses from both the relations are added to the
* other remote clauses. For LEFT and RIGHT OUTER join, the clauses from
--- 4155,4176 ----
fpinfo->jointype = jointype;
/*
+ * By default both the joining relations are not required to be deparsed as
+ * subqueries. But there might be some relations covered by the joining
+ * relations that are required to be deparsed as subqueries, so save the
+ * relids of those relations for later use of deparser.
+ */
+ fpinfo->make_outerrel_subquery = false;
+ fpinfo->make_innerrel_subquery = false;
+ Assert(bms_is_subset(fpinfo_i->subquery_rels, innerrel->relids));
+ Assert(bms_is_subset(fpinfo_o->subquery_rels, outerrel->relids));
+ fpinfo->subquery_rels = bms_union(fpinfo_i->subquery_rels,
+ fpinfo_o->subquery_rels);
+
+ /*
* Pull the other remote conditions from the joining relations into join
* clauses or other remote clauses (remote_conds) of this relation
! * wherever possible. This avoids building subqueries at every join step.
*
* For an inner join, clauses from both the relations are added to the
* other remote clauses. For LEFT and RIGHT OUTER join, the clauses from
***************
*** 4161,4168 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
*
* For a FULL OUTER JOIN, the other clauses from either relation can not
* be added to the joinclauses or remote_conds, since each relation acts
! * as an outer relation for the other. Consider such full outer join as
! * unshippable because of the reasons mentioned above in this comment.
*
* The joining sides can not have local conditions, thus no need to test
* shippability of the clauses being pulled up.
--- 4181,4187 ----
*
* For a FULL OUTER JOIN, the other clauses from either relation can not
* be added to the joinclauses or remote_conds, since each relation acts
! * as an outer relation for the other.
*
* The joining sides can not have local conditions, thus no need to test
* shippability of the clauses being pulled up.
***************
*** 4191,4198 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
break;
case JOIN_FULL:
! if (fpinfo_i->remote_conds || fpinfo_o->remote_conds)
! return false;
break;
default:
--- 4210,4236 ----
break;
case JOIN_FULL:
!
! /*
! * In this case, if any of the joining relations has conditions,
! * we need to deparse that relation as a subquery so that
! * conditions can be evaluated before the join. Remember it in
! * the fpinfo so that deparser can take appropriate action. We
! * also save the relids of that relation that is covered by the
! * subquery for later use of deparser.
! */
! if (fpinfo_o->remote_conds)
! {
! fpinfo->make_outerrel_subquery = true;
! fpinfo->subquery_rels = bms_add_members(fpinfo->subquery_rels,
! outerrel->relids);
! }
! if (fpinfo_i->remote_conds)
! {
! fpinfo->make_innerrel_subquery = true;
! fpinfo->subquery_rels = bms_add_members(fpinfo->subquery_rels,
! innerrel->relids);
! }
break;
default:
***************
*** 4273,4278 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
--- 4311,4326 ----
get_jointype_name(fpinfo->jointype),
fpinfo_i->relation_name->data);
+ /*
+ * Set the relation index. This is defined as the position of this
+ * joinrel in the join_rel_list list plus the length of the rtable list.
+ * Note that since this joinrel is at the end of the list when we are
+ * called, we can get the position by list_length.
+ */
+ Assert(fpinfo->relation_index == 0);
+ fpinfo->relation_index =
+ list_length(root->parse->rtable) + list_length(root->join_rel_list);
+
return true;
}
*** a/contrib/postgres_fdw/postgres_fdw.h
--- b/contrib/postgres_fdw/postgres_fdw.h
***************
*** 95,100 **** typedef struct PgFdwRelationInfo
--- 95,113 ----
/* Grouping information */
List *grouped_tlist;
+
+ /* Subquery information */
+ bool make_outerrel_subquery; /* do we deparse outerrel as a
+ * subquery? */
+ bool make_innerrel_subquery; /* do we deparse innerrel as a
+ * subquery? */
+ Relids subquery_rels; /* all relids appearing in lower subqueries */
+
+ /*
+ * Index of the relation. It is used for creating a subselect alias when
+ * deparsing the relation as a subquery.
+ */
+ int relation_index;
} PgFdwRelationInfo;
/* in postgres_fdw.c */
*** a/contrib/postgres_fdw/sql/postgres_fdw.sql
--- b/contrib/postgres_fdw/sql/postgres_fdw.sql
***************
*** 391,399 **** EXPLAIN (VERBOSE, COSTS OFF)
--- 391,409 ----
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 45 LIMIT 10;
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 45 LIMIT 10;
-- full outer join with restrictions on the joining relations
+ -- a. the joining relations are both base relations
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1;
SELECT t1.c1, t2.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1;
+ -- b. one of the joining relations is a base relation and the other is a join
+ -- relation
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM ft4 t2 LEFT JOIN ft5 t3 ON (t2.c1 = t3.c1) WHERE (t2.c1 between 50 and 60)) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM ft4 t2 LEFT JOIN ft5 t3 ON (t2.c1 = t3.c1) WHERE (t2.c1 between 50 and 60)) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
+ -- c. test deparsing the remote query as nested subqueries
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t2 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t3 ON (t2.c1 = t3.c1) WHERE t2.c1 IS NULL OR t2.c1 IS NOT NULL) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
+ SELECT t1.c1, ss.a, ss.b FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t1 FULL JOIN (SELECT t2.c1, t3.c1 FROM (SELECT c1 FROM ft4 WHERE c1 between 50 and 60) t2 FULL JOIN (SELECT c1 FROM ft5 WHERE c1 between 50 and 60) t3 ON (t2.c1 = t3.c1) WHERE t2.c1 IS NULL OR t2.c1 IS NOT NULL) ss(a, b) ON (t1.c1 = ss.a) ORDER BY t1.c1, ss.a, ss.b;
-- full outer join + inner join
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1, t3.c1 FROM ft4 t1 INNER JOIN ft5 t2 ON (t1.c1 = t2.c1 + 1 and t1.c1 between 50 and 60) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) ORDER BY t1.c1, t2.c1, t3.c1 LIMIT 10;
***************
*** 793,798 **** explain (verbose, costs off)
--- 803,814 ----
select avg(t1.c1), sum(t2.c1) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) group by t2.c1 having (avg(t1.c1) is null and sum(t2.c1) < 10) or sum(t2.c1) is null order by 1 nulls last, 2;
select avg(t1.c1), sum(t2.c1) from ft4 t1 full join ft5 t2 on (t1.c1 = t2.c1) group by t2.c1 having (avg(t1.c1) is null and sum(t2.c1) < 10) or sum(t2.c1) is null order by 1 nulls last, 2;
+ -- Aggregate over FULL join needing to deparse the joining relations as
+ -- subqueries.
+ explain (verbose, costs off)
+ select count(*), sum(t1.c1), avg(t2.c1) from (select c1 from ft4 where c1 between 50 and 60) t1 full join (select c1 from ft5 where c1 between 50 and 60) t2 on (t1.c1 = t2.c1);
+ select count(*), sum(t1.c1), avg(t2.c1) from (select c1 from ft4 where c1 between 50 and 60) t1 full join (select c1 from ft5 where c1 between 50 and 60) t2 on (t1.c1 = t2.c1);
+
-- ORDER BY expression is part of the target list but not pushed down to
-- foreign server.
explain (verbose, costs off)
*** a/contrib/postgres_fdw/deparse.c
--- b/contrib/postgres_fdw/deparse.c
***************
*** 49,54 ****
--- 49,55 ----
#include "nodes/nodeFuncs.h"
#include "nodes/plannodes.h"
#include "optimizer/clauses.h"
+ #include "optimizer/placeholder.h"
#include "optimizer/prep.h"
#include "optimizer/tlist.h"
#include "optimizer/var.h"
***************
*** 157,162 **** static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
--- 158,164 ----
static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
+ static void deparseExprInPlaceHolderVar(PlaceHolderVar *node, deparse_expr_cxt *context);
static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
deparse_expr_cxt *context);
static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
***************
*** 172,180 **** static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
bool make_subquery, List **params_list);
static void appendSubselectAlias(StringInfo buf, int tabno, int ncols);
! static void getSubselectAliasInfo(Var *node, RelOptInfo *foreignrel,
int *tabno, int *colno);
! static bool isSubqueryExpr(Var *node, RelOptInfo *foreignrel, int *tabno, int *colno);
static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
static void appendAggOrderBy(List *orderList, List *targetList,
--- 174,183 ----
static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
bool make_subquery, List **params_list);
static void appendSubselectAlias(StringInfo buf, int tabno, int ncols);
! static void getSubselectAliasInfo(Expr *node, RelOptInfo *foreignrel,
int *tabno, int *colno);
! static bool isSubqueryExpr(Expr *node, PlannerInfo *root, RelOptInfo *foreignrel,
! int *tabno, int *colno);
static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
static void appendAggOrderBy(List *orderList, List *targetList,
***************
*** 765,770 **** foreign_expr_walker(Node *node,
--- 768,792 ----
state = FDW_COLLATE_UNSAFE;
}
break;
+ case T_PlaceHolderVar:
+ {
+ PlaceHolderVar *phv = (PlaceHolderVar *) node;
+ PlaceHolderInfo *phinfo = find_placeholder_info(glob_cxt->root,
+ phv, false);
+
+ /*
+ * If the PHV's contained expression is computable on the
+ * remote server, we consider the PHV safe to send.
+ */
+ if (phv->phlevelsup == 0 &&
+ bms_is_subset(phinfo->ph_eval_at,
+ glob_cxt->foreignrel->relids))
+ return foreign_expr_walker((Node *) phv->phexpr,
+ glob_cxt, outer_cxt);
+ else
+ return false;
+ }
+ break;
default:
/*
***************
*** 859,865 **** deparse_type_name(Oid type_oid, int32 typemod)
* foreign server.
*/
List *
! build_tlist_to_deparse(RelOptInfo *foreignrel)
{
List *tlist = NIL;
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
--- 881,887 ----
* foreign server.
*/
List *
! build_tlist_to_deparse(PlannerInfo *root, RelOptInfo *foreignrel)
{
List *tlist = NIL;
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
***************
*** 872,886 **** build_tlist_to_deparse(RelOptInfo *foreignrel)
return fpinfo->grouped_tlist;
/*
! * We require columns specified in foreignrel->reltarget->exprs and those
! * required for evaluating the local conditions.
*/
! tlist = add_to_flat_tlist(tlist,
! pull_var_clause((Node *) foreignrel->reltarget->exprs,
! PVC_RECURSE_PLACEHOLDERS));
! tlist = add_to_flat_tlist(tlist,
! pull_var_clause((Node *) fpinfo->local_conds,
! PVC_RECURSE_PLACEHOLDERS));
return tlist;
}
--- 894,966 ----
return fpinfo->grouped_tlist;
/*
! * Fetch all expressions in foreignrel's reltarget if the
! * reltarget_is_shippable flag is set TRUE. Otherwise, fetch shipplable
! * expressions in the reltarget plus expressions required for evaluating
! * non-shippable expressions in the reltarget.
! */
! if (fpinfo->reltarget_is_shippable)
! tlist = make_tlist_from_pathtarget(foreignrel->reltarget);
! else
! {
! List *exprs = NIL;
! ListCell *lc;
!
! /* Note: we have at least one non-shippable PHV in the reltarget. */
! foreach(lc, foreignrel->reltarget->exprs)
! {
! Node *node = (Node *) lfirst(lc);
!
! if (IsA(node, Var))
! exprs = lappend(exprs, node);
! else if (IsA(node, PlaceHolderVar))
! {
! PlaceHolderVar *phv = (PlaceHolderVar *) node;
! PlaceHolderInfo *phinfo = find_placeholder_info(root, phv,
! false);
!
! if (bms_is_subset(phinfo->ph_eval_at,
! fpinfo->outerrel->relids) ||
! bms_is_subset(phinfo->ph_eval_at,
! fpinfo->innerrel->relids))
! {
! /*
! * The PHV coming from an either input should be shippable.
! */
! exprs = lappend(exprs, node);
! }
! else
! {
! /*
! * The PHV might be shippable, but in any case just fetch
! * expressions required for evaluating the PHV.
! */
! List *exprs2 = pull_var_clause(node,
! PVC_INCLUDE_PLACEHOLDERS);
! ListCell *lc2;
!
! foreach(lc2, exprs2)
! {
! Node *node2 = (Node *) lfirst(lc2);
!
! exprs = lappend(exprs, node2);
! }
! }
! }
! else
! elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
! }
!
! tlist = add_to_flat_tlist(tlist, exprs);
! }
!
! /*
! * Fetch expressions required for evaluating local conditions, if any.
*/
! if (fpinfo->local_conds)
! tlist = add_to_flat_tlist(tlist,
! pull_var_clause((Node *) fpinfo->local_conds,
! PVC_INCLUDE_PLACEHOLDERS));
return tlist;
}
***************
*** 1451,1457 **** deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
Assert(foreignrel->reloptkind == RELOPT_BASEREL ||
foreignrel->reloptkind == RELOPT_JOINREL);
! Assert(fpinfo->local_conds == NIL);
if (make_subquery)
{
--- 1531,1537 ----
Assert(foreignrel->reloptkind == RELOPT_BASEREL ||
foreignrel->reloptkind == RELOPT_JOINREL);
! Assert(fpinfo->reltarget_is_shippable && fpinfo->local_conds == NIL);
if (make_subquery)
{
***************
*** 1506,1512 **** appendSubselectAlias(StringInfo buf, int tabno, int ncols)
* respectively.
*/
static void
! getSubselectAliasInfo(Var *node, RelOptInfo *foreignrel,
int *tabno, int *colno)
{
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
--- 1586,1592 ----
* respectively.
*/
static void
! getSubselectAliasInfo(Expr *node, RelOptInfo *foreignrel,
int *tabno, int *colno)
{
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
***************
*** 1539,1549 **** getSubselectAliasInfo(Var *node, RelOptInfo *foreignrel,
* respectively, in that case.
*/
static bool
! isSubqueryExpr(Var *node, RelOptInfo *foreignrel, int *tabno, int *colno)
{
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
RelOptInfo *outerrel = fpinfo->outerrel;
RelOptInfo *innerrel = fpinfo->innerrel;
if (foreignrel->reloptkind != RELOPT_JOINREL)
return false;
--- 1619,1631 ----
* respectively, in that case.
*/
static bool
! isSubqueryExpr(Expr *node, PlannerInfo *root, RelOptInfo *foreignrel,
! int *tabno, int *colno)
{
PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
RelOptInfo *outerrel = fpinfo->outerrel;
RelOptInfo *innerrel = fpinfo->innerrel;
+ bool is_outer_var;
if (foreignrel->reloptkind != RELOPT_JOINREL)
return false;
***************
*** 1551,1557 **** isSubqueryExpr(Var *node, RelOptInfo *foreignrel, int *tabno, int *colno)
if (!fpinfo->subquery_rels)
return false;
! if (bms_is_member(node->varno, outerrel->relids))
{
/*
* If outer relation is deparsed as a subqeury, the given expression
--- 1633,1664 ----
if (!fpinfo->subquery_rels)
return false;
! if (IsA(node, Var))
! {
! Var *var = (Var *) node;
!
! is_outer_var = bms_is_member(var->varno, outerrel->relids);
! }
! else if (IsA(node, PlaceHolderVar))
! {
! PlaceHolderVar *phv = (PlaceHolderVar *) node;
! PlaceHolderInfo *phinfo = find_placeholder_info(root, phv, false);
! bool is_inner_var;
!
! is_outer_var = bms_is_subset(phinfo->ph_eval_at, outerrel->relids);
! is_inner_var = bms_is_subset(phinfo->ph_eval_at, innerrel->relids);
!
! /*
! * If the PHV can't be computed in either input, it should be computed
! * in the current join level, so it's not a subquery output column.
! */
! if (!is_outer_var && !is_inner_var)
! return false;
! }
! else
! elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
!
! if (is_outer_var)
{
/*
* If outer relation is deparsed as a subqeury, the given expression
***************
*** 1564,1576 **** isSubqueryExpr(Var *node, RelOptInfo *foreignrel, int *tabno, int *colno)
return true;
}
/* Otherwise, recurse into outer relation */
! if (isSubqueryExpr(node, outerrel, tabno, colno))
return true;
}
else
{
- Assert(bms_is_member(node->varno, innerrel->relids));
-
/*
* Likewise for inner relation
*/
--- 1671,1681 ----
return true;
}
/* Otherwise, recurse into outer relation */
! if (isSubqueryExpr(node, root, outerrel, tabno, colno))
return true;
}
else
{
/*
* Likewise for inner relation
*/
***************
*** 1579,1585 **** isSubqueryExpr(Var *node, RelOptInfo *foreignrel, int *tabno, int *colno)
getSubselectAliasInfo(node, innerrel, tabno, colno);
return true;
}
! if (isSubqueryExpr(node, innerrel, tabno, colno))
return true;
}
return false;
--- 1684,1690 ----
getSubselectAliasInfo(node, innerrel, tabno, colno);
return true;
}
! if (isSubqueryExpr(node, root, innerrel, tabno, colno))
return true;
}
return false;
***************
*** 1966,1974 **** deparseColumnRef(StringInfo buf, int varno, int varattno, PlannerInfo *root,
{
/*
* All other system attributes are fetched as 0, except for table OID,
! * which is fetched as the local table OID. However, we must be
! * careful; the table could be beneath an outer join, in which case it
! * must go to NULL whenever the rest of the row does.
*/
Oid fetchval = 0;
--- 2071,2077 ----
{
/*
* All other system attributes are fetched as 0, except for table OID,
! * which is fetched as the local table OID.
*/
Oid fetchval = 0;
***************
*** 1978,1991 **** deparseColumnRef(StringInfo buf, int varno, int varattno, PlannerInfo *root,
fetchval = rte->relid;
}
! if (qualify_col)
! {
! appendStringInfoString(buf, "CASE WHEN (");
! ADD_REL_QUALIFIER(buf, varno);
! appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
! }
! else
! appendStringInfo(buf, "%u", fetchval);
}
else if (varattno == 0)
{
--- 2081,2087 ----
fetchval = rte->relid;
}
! appendStringInfo(buf, "%u", fetchval);
}
else if (varattno == 0)
{
***************
*** 2016,2043 **** deparseColumnRef(StringInfo buf, int varno, int varattno, PlannerInfo *root,
attrs_used = bms_add_member(NULL,
0 - FirstLowInvalidHeapAttributeNumber);
- /*
- * In case the whole-row reference is under an outer join then it has
- * to go NULL whenever the rest of the row goes NULL. Deparsing a join
- * query would always involve multiple relations, thus qualify_col
- * would be true.
- */
- if (qualify_col)
- {
- appendStringInfoString(buf, "CASE WHEN (");
- ADD_REL_QUALIFIER(buf, varno);
- appendStringInfo(buf, "*)::text IS NOT NULL THEN ");
- }
-
appendStringInfoString(buf, "ROW(");
deparseTargetList(buf, root, varno, rel, false, attrs_used, qualify_col,
&retrieved_attrs);
appendStringInfoString(buf, ")");
- /* Complete the CASE WHEN statement started above. */
- if (qualify_col)
- appendStringInfo(buf, " END");
-
heap_close(rel, NoLock);
bms_free(attrs_used);
}
--- 2112,2122 ----
***************
*** 2210,2215 **** deparseExpr(Expr *node, deparse_expr_cxt *context)
--- 2289,2297 ----
case T_Aggref:
deparseAggref((Aggref *) node, context);
break;
+ case T_PlaceHolderVar:
+ deparseExprInPlaceHolderVar((PlaceHolderVar *) node, context);
+ break;
default:
elog(ERROR, "unsupported expression type for deparse: %d",
(int) nodeTag(node));
***************
*** 2229,2234 **** static void
--- 2311,2317 ----
deparseVar(Var *node, deparse_expr_cxt *context)
{
Relids relids = context->scanrel->relids;
+ PlannerInfo *root = context->root;
RelOptInfo *rel = (context->foreignrel->reloptkind == RELOPT_UPPER_REL) ?
context->scanrel : context->foreignrel;
int tabno;
***************
*** 2241,2247 **** deparseVar(Var *node, deparse_expr_cxt *context)
* If the given Var is an output column of a subquery-in-FROM, deparse
* the alias to the given Var instead.
*/
! if (isSubqueryExpr(node, rel, &tabno, &colno))
{
appendStringInfo(context->buf, "%s%d.%s%d",
SS_TAB_ALIAS_PREFIX, tabno,
--- 2324,2330 ----
* If the given Var is an output column of a subquery-in-FROM, deparse
* the alias to the given Var instead.
*/
! if (isSubqueryExpr((Expr *) node, root, rel, &tabno, &colno))
{
appendStringInfo(context->buf, "%s%d.%s%d",
SS_TAB_ALIAS_PREFIX, tabno,
***************
*** 2935,2940 **** appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
--- 3018,3050 ----
}
/*
+ * Deparse a PlaceHolderVar's contained expression.
+ */
+ static void
+ deparseExprInPlaceHolderVar(PlaceHolderVar *node, deparse_expr_cxt *context)
+ {
+ PlannerInfo *root = context->root;
+ RelOptInfo *rel = (context->foreignrel->reloptkind == RELOPT_UPPER_REL) ?
+ context->scanrel : context->foreignrel;
+ int tabno;
+ int colno;
+
+ /*
+ * If the given PHV is an output column of a subquery-in-FROM, deparse
+ * the alias to the given PHV instead.
+ */
+ if (isSubqueryExpr((Expr *) node, root, rel, &tabno, &colno))
+ {
+ appendStringInfo(context->buf, "%s%d.%s%d",
+ SS_TAB_ALIAS_PREFIX, tabno,
+ SS_COL_ALIAS_PREFIX, colno);
+ return;
+ }
+
+ deparseExpr(node->phexpr, context);
+ }
+
+ /*
* Print the representation of a parameter to be sent to the remote side.
*
* Note: we always label the Param's type explicitly rather than relying on
*** a/contrib/postgres_fdw/expected/postgres_fdw.out
--- b/contrib/postgres_fdw/expected/postgres_fdw.out
***************
*** 1547,1554 **** SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) WHERE (t1.c1
-- tests whole-row reference for row marks
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE OF t1;
! QUERY PLAN
! -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
--- 1547,1554 ----
-- tests whole-row reference for row marks
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE OF t1;
! QUERY PLAN
! ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
***************
*** 1556,1562 **** SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT r1."C 1", r1.c3, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, r2."C 1", CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR UPDATE OF r1
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
--- 1556,1562 ----
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT s1.c1, s1.c2, s1.c3, s2.c1, s2.c2 FROM ((SELECT "C 1", c3, ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1" FOR UPDATE) s1(c1, c2, c3) INNER JOIN (SELECT "C 1", ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1") s2(c1, c2) ON (((s1.c1 = s2.c1)))) ORDER BY s1.c2 ASC NULLS LAST, s1.c1 ASC NULLS LAST
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
***************
*** 1591,1598 **** SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE;
! QUERY PLAN
! ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
--- 1591,1598 ----
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE;
! QUERY PLAN
! ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
***************
*** 1600,1606 **** SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT r1."C 1", r1.c3, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, r2."C 1", CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR UPDATE OF r1 FOR UPDATE OF r2
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
--- 1600,1606 ----
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT s1.c1, s1.c2, s1.c3, s2.c1, s2.c2 FROM ((SELECT "C 1", c3, ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1" FOR UPDATE) s1(c1, c2, c3) INNER JOIN (SELECT "C 1", ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1" FOR UPDATE) s2(c1, c2) ON (((s1.c1 = s2.c1)))) ORDER BY s1.c2 ASC NULLS LAST, s1.c1 ASC NULLS LAST
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
***************
*** 1636,1643 **** SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
-- join two tables with FOR SHARE clause
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE OF t1;
! QUERY PLAN
! ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
--- 1636,1643 ----
-- join two tables with FOR SHARE clause
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE OF t1;
! QUERY PLAN
! ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
***************
*** 1645,1651 **** SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT r1."C 1", r1.c3, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, r2."C 1", CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR SHARE OF r1
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
--- 1645,1651 ----
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT s1.c1, s1.c2, s1.c3, s2.c1, s2.c2 FROM ((SELECT "C 1", c3, ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1" FOR SHARE) s1(c1, c2, c3) INNER JOIN (SELECT "C 1", ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1") s2(c1, c2) ON (((s1.c1 = s2.c1)))) ORDER BY s1.c2 ASC NULLS LAST, s1.c1 ASC NULLS LAST
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
***************
*** 1680,1687 **** SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE;
! QUERY PLAN
! --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
--- 1680,1687 ----
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE;
! QUERY PLAN
! -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
-> LockRows
***************
*** 1689,1695 **** SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT r1."C 1", r1.c3, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, r2."C 1", CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST FOR SHARE OF r1 FOR SHARE OF r2
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
--- 1689,1695 ----
-> Foreign Scan
Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT s1.c1, s1.c2, s1.c3, s2.c1, s2.c2 FROM ((SELECT "C 1", c3, ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1" FOR SHARE) s1(c1, c2, c3) INNER JOIN (SELECT "C 1", ROW("C 1", c2, c3, c4, c5, c6, c7, c8) FROM "S 1"."T 1" FOR SHARE) s2(c1, c2) ON (((s1.c1 = s2.c1)))) ORDER BY s1.c2 ASC NULLS LAST, s1.c1 ASC NULLS LAST
-> Merge Join
Output: t1.c1, t1.c3, t1.*, t2.c1, t2.*
Merge Cond: (t1.c1 = t2.c1)
***************
*** 1759,1772 **** WITH t (c1_1, c1_3, c2_1) AS (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2
-- ctid with whole-row reference
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.ctid, t1, t2, t1.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10;
! QUERY PLAN
! -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.ctid, t1.*, t2.*, t1.c1, t1.c3
-> Foreign Scan
Output: t1.ctid, t1.*, t2.*, t1.c1, t1.c3
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT r1.ctid, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, r1."C 1", r1.c3, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST
(6 rows)
-- SEMI JOIN, not pushed down
--- 1759,1772 ----
-- ctid with whole-row reference
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.ctid, t1, t2, t1.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10;
! QUERY PLAN
! ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.ctid, t1.*, t2.*, t1.c1, t1.c3
-> Foreign Scan
Output: t1.ctid, t1.*, t2.*, t1.c1, t1.c3
Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
! Remote SQL: SELECT s1.c1, s1.c2, s1.c3, s1.c4, s2.c1 FROM ((SELECT ctid, ROW("C 1", c2, c3, c4, c5, c6, c7, c8), "C 1", c3 FROM "S 1"."T 1") s1(c1, c2, c3, c4) INNER JOIN (SELECT ROW("C 1", c2, c3, c4, c5, c6, c7, c8), "C 1" FROM "S 1"."T 1") s2(c1, c2) ON (((s1.c3 = s2.c2)))) ORDER BY s1.c4 ASC NULLS LAST, s1.c3 ASC NULLS LAST
(6 rows)
-- SEMI JOIN, not pushed down
***************
*** 2095,2119 **** SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM
1
(10 rows)
! -- non-Var items in targelist of the nullable rel of a join preventing
! -- push-down in some cases
! -- unable to push {ft1, ft2}
EXPLAIN (VERBOSE, COSTS OFF)
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
! QUERY PLAN
! ---------------------------------------------------------------------------------------------------------------------------
! Nested Loop Left Join
Output: (13), ft2.c1
! Join Filter: (13 = ft2.c1)
! -> Foreign Scan on public.ft2
! Output: ft2.c1
! Remote SQL: SELECT "C 1" FROM "S 1"."T 1" WHERE (("C 1" >= 10)) AND (("C 1" <= 15)) ORDER BY "C 1" ASC NULLS LAST
! -> Materialize
! Output: (13)
! -> Foreign Scan on public.ft1
! Output: 13
! Remote SQL: SELECT NULL FROM "S 1"."T 1" WHERE (("C 1" = 13))
! (11 rows)
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
a | c1
--- 2095,2110 ----
1
(10 rows)
! -- check join pushdown in situations where PHVs are involved
EXPLAIN (VERBOSE, COSTS OFF)
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
! QUERY PLAN
! ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
! Foreign Scan
Output: (13), ft2.c1
! Relations: (public.ft2) LEFT JOIN (public.ft1)
! Remote SQL: SELECT r2."C 1", s4.c1 FROM ("S 1"."T 1" r2 LEFT JOIN (SELECT 13 FROM "S 1"."T 1" WHERE (("C 1" = 13))) s4(c1) ON (((13 = r2."C 1")))) WHERE ((r2."C 1" >= 10)) AND ((r2."C 1" <= 15))
! (4 rows)
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
a | c1
***************
*** 2126,2149 **** SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 O
| 15
(6 rows)
- -- ok to push {ft1, ft2} but not {ft1, ft2, ft4}
EXPLAIN (VERBOSE, COSTS OFF)
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
! QUERY PLAN
! -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
! Nested Loop Left Join
Output: ft4.c1, (13), ft1.c1, ft2.c1
! Join Filter: (ft4.c1 = ft1.c1)
! -> Foreign Scan on public.ft4
! Output: ft4.c1, ft4.c2, ft4.c3
! Remote SQL: SELECT c1 FROM "S 1"."T 3" WHERE ((c1 >= 10)) AND ((c1 <= 15))
! -> Materialize
! Output: ft1.c1, ft2.c1, (13)
! -> Foreign Scan
! Output: ft1.c1, ft2.c1, 13
! Relations: (public.ft1) INNER JOIN (public.ft2)
! Remote SQL: SELECT r4."C 1", r5."C 1" FROM ("S 1"."T 1" r4 INNER JOIN "S 1"."T 1" r5 ON (((r5."C 1" = 12)) AND ((r4."C 1" = 12)))) ORDER BY r4."C 1" ASC NULLS LAST
! (12 rows)
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
c1 | a | b | c
--- 2117,2131 ----
| 15
(6 rows)
EXPLAIN (VERBOSE, COSTS OFF)
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
! QUERY PLAN
! ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
! Foreign Scan
Output: ft4.c1, (13), ft1.c1, ft2.c1
! Relations: (public.ft4) LEFT JOIN ((public.ft1) INNER JOIN (public.ft2))
! Remote SQL: SELECT r1.c1, s7.c1, s7.c2, s7.c3 FROM ("S 1"."T 3" r1 LEFT JOIN (SELECT r4."C 1", r5."C 1", 13 FROM ("S 1"."T 1" r4 INNER JOIN "S 1"."T 1" r5 ON (((r5."C 1" = 12)) AND ((r4."C 1" = 12))))) s7(c1, c2, c3) ON (((r1.c1 = s7.c1)))) WHERE ((r1.c1 >= 10)) AND ((r1.c1 <= 15))
! (4 rows)
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
c1 | a | b | c
***************
*** 2153,2168 **** SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT
14 | | |
(3 rows)
-- join with nullable side with some columns with null values
UPDATE ft5 SET c3 = null where c1 % 9 = 0;
EXPLAIN (VERBOSE, COSTS OFF)
SELECT ft5, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2 FROM ft5 left join ft4 on ft5.c1 = ft4.c1 WHERE ft4.c1 BETWEEN 10 and 30 ORDER BY ft5.c1, ft4.c1;
! QUERY PLAN
! ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: ft5.*, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2
Relations: (public.ft5) INNER JOIN (public.ft4)
! Remote SQL: SELECT CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1.c1, r1.c2, r1.c3) END, r1.c1, r1.c2, r1.c3, r2.c1, r2.c2 FROM ("S 1"."T 4" r1 INNER JOIN "S 1"."T 3" r2 ON (((r1.c1 = r2.c1)) AND ((r2.c1 >= 10)) AND ((r2.c1 <= 30)))) ORDER BY r1.c1 ASC NULLS LAST
(4 rows)
SELECT ft5, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2 FROM ft5 left join ft4 on ft5.c1 = ft4.c1 WHERE ft4.c1 BETWEEN 10 and 30 ORDER BY ft5.c1, ft4.c1;
--- 2135,2215 ----
14 | | |
(3 rows)
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT ft2.c1, q2.* FROM ft2 LEFT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2) WHERE ft2.c1 BETWEEN 10 AND 15;
+ QUERY PLAN
+ -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: ft2.c1, (13), (13), ft2_1.c1
+ Relations: (public.ft2) LEFT JOIN ((public.ft2) LEFT JOIN (public.ft1))
+ Remote SQL: SELECT r1."C 1", s8.c1, s8.c2, s8.c3 FROM ("S 1"."T 1" r1 LEFT JOIN (SELECT r5."C 1", 13, s7.c1 FROM ("S 1"."T 1" r5 LEFT JOIN (SELECT 13 FROM "S 1"."T 1" WHERE (("C 1" = 13))) s7(c1) ON (((13 = r5."C 1")))) WHERE ((r5."C 1" >= 10)) AND ((r5."C 1" <= 15))) s8(c1, c2, c3) ON (((r1."C 1" = 13)))) WHERE ((r1."C 1" >= 10)) AND ((r1."C 1" <= 15))
+ (4 rows)
+
+ SELECT ft2.c1, q2.* FROM ft2 LEFT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2) WHERE ft2.c1 BETWEEN 10 AND 15;
+ c1 | a2 | b2 | c2
+ ----+----+----+----
+ 10 | | |
+ 11 | | |
+ 12 | | |
+ 13 | 13 | | 10
+ 13 | 13 | | 11
+ 13 | 13 | | 12
+ 13 | 13 | 13 | 13
+ 13 | 13 | | 14
+ 13 | 13 | | 15
+ 14 | | |
+ 15 | | |
+ (11 rows)
+
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT ft2.c1, q2.* FROM ft2 RIGHT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2);
+ QUERY PLAN
+ ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: ft2.c1, 13, (13), ft2_1.c1
+ Relations: ((public.ft2) LEFT JOIN (public.ft1)) LEFT JOIN (public.ft2)
+ Remote SQL: SELECT r5."C 1", r1."C 1", s7.c1 FROM (("S 1"."T 1" r5 LEFT JOIN (SELECT 13 FROM "S 1"."T 1" WHERE (("C 1" = 13))) s7(c1) ON (((13 = r5."C 1")))) LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = 13)))) WHERE ((r5."C 1" >= 10)) AND ((r5."C 1" <= 15))
+ (4 rows)
+
+ SELECT ft2.c1, q2.* FROM ft2 RIGHT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2);
+ c1 | a2 | b2 | c2
+ ----+----+----+----
+ 13 | 13 | | 10
+ 13 | 13 | | 11
+ 13 | 13 | | 12
+ 13 | 13 | 13 | 13
+ 13 | 13 | | 14
+ 13 | 13 | | 15
+ (6 rows)
+
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT ft4.c1, q2.* FROM ft4 LEFT JOIN (SELECT (q.a IS NOT NULL), ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15) q2(a2, b2, c2, d2, e2) ON (ft4.c1 = q2.b2) WHERE ft4.c1 BETWEEN 10 AND 15;
+ QUERY PLAN
+ ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: ft4.c1, ((13 IS NOT NULL)), ft4_1.c1, (13), ft1.c1, ft2.c1
+ Relations: (public.ft4) LEFT JOIN ((public.ft4) LEFT JOIN ((public.ft1) INNER JOIN (public.ft2)))
+ Remote SQL: SELECT r1.c1, s11.c1, s11.c2, s11.c3, s11.c4, s11.c5 FROM ("S 1"."T 3" r1 LEFT JOIN (SELECT r4.c1, s10.c1, s10.c2, (s10.c3 IS NOT NULL), s10.c3 FROM ("S 1"."T 3" r4 LEFT JOIN (SELECT r7."C 1", r8."C 1", 13 FROM ("S 1"."T 1" r7 INNER JOIN "S 1"."T 1" r8 ON (((r8."C 1" = 12)) AND ((r7."C 1" = 12))))) s10(c1, c2, c3) ON (((r4.c1 = s10.c1)))) WHERE ((r4.c1 >= 10)) AND ((r4.c1 <= 15))) s11(c1, c2, c3, c4, c5) ON (((r1.c1 = s11.c1)))) WHERE ((r1.c1 >= 10)) AND ((r1.c1 <= 15))
+ (4 rows)
+
+ SELECT ft4.c1, q2.* FROM ft4 LEFT JOIN (SELECT (q.a IS NOT NULL), ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15) q2(a2, b2, c2, d2, e2) ON (ft4.c1 = q2.b2) WHERE ft4.c1 BETWEEN 10 AND 15;
+ c1 | a2 | b2 | c2 | d2 | e2
+ ----+----+----+----+----+----
+ 10 | f | 10 | | |
+ 12 | t | 12 | 13 | 12 | 12
+ 14 | f | 14 | | |
+ (3 rows)
+
-- join with nullable side with some columns with null values
UPDATE ft5 SET c3 = null where c1 % 9 = 0;
EXPLAIN (VERBOSE, COSTS OFF)
SELECT ft5, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2 FROM ft5 left join ft4 on ft5.c1 = ft4.c1 WHERE ft4.c1 BETWEEN 10 and 30 ORDER BY ft5.c1, ft4.c1;
! QUERY PLAN
! ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Foreign Scan
Output: ft5.*, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2
Relations: (public.ft5) INNER JOIN (public.ft4)
! Remote SQL: SELECT s1.c1, s1.c2, s1.c3, s1.c4, r2.c1, r2.c2 FROM ((SELECT ROW(c1, c2, c3), c1, c2, c3 FROM "S 1"."T 4") s1(c1, c2, c3, c4) INNER JOIN "S 1"."T 3" r2 ON (((s1.c2 = r2.c1)) AND ((r2.c1 >= 10)) AND ((r2.c1 <= 30)))) ORDER BY s1.c2 ASC NULLS LAST
(4 rows)
SELECT ft5, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2 FROM ft5 left join ft4 on ft5.c1 = ft4.c1 WHERE ft4.c1 BETWEEN 10 and 30 ORDER BY ft5.c1, ft4.c1;
***************
*** 4064,4077 **** UPDATE ft2 SET c2 = c2 + 400, c3 = c3 || '_update7' WHERE c1 % 10 = 7 RETURNING
EXPLAIN (verbose, costs off)
UPDATE ft2 SET c2 = ft2.c2 + 500, c3 = ft2.c3 || '_update9', c7 = DEFAULT
FROM ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 9; -- can't be pushed down
! QUERY PLAN
! ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Update on public.ft2
Remote SQL: UPDATE "S 1"."T 1" SET c2 = $2, c3 = $3, c7 = $4 WHERE ctid = $1
-> Foreign Scan
Output: ft2.c1, (ft2.c2 + 500), NULL::integer, (ft2.c3 || '_update9'::text), ft2.c4, ft2.c5, ft2.c6, 'ft2 '::character(10), ft2.c8, ft2.ctid, ft1.*
Relations: (public.ft2) INNER JOIN (public.ft1)
! Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c8, r1.ctid, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1.c2 = r2."C 1")) AND (((r2."C 1" % 10) = 9)))) FOR UPDATE OF r1
-> Hash Join
Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c8, ft2.ctid, ft1.*
Hash Cond: (ft2.c2 = ft1.c1)
--- 4111,4124 ----
EXPLAIN (verbose, costs off)
UPDATE ft2 SET c2 = ft2.c2 + 500, c3 = ft2.c3 || '_update9', c7 = DEFAULT
FROM ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 9; -- can't be pushed down
! QUERY PLAN
! --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Update on public.ft2
Remote SQL: UPDATE "S 1"."T 1" SET c2 = $2, c3 = $3, c7 = $4 WHERE ctid = $1
-> Foreign Scan
Output: ft2.c1, (ft2.c2 + 500), NULL::integer, (ft2.c3 || '_update9'::text), ft2.c4, ft2.c5, ft2.c6, 'ft2 '::character(10), ft2.c8, ft2.ctid, ft1.*
Relations: (public.ft2) INNER JOIN (public.ft1)
! Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c8, r1.ctid, s2.c1 FROM ("S 1"."T 1" r1 INNER JOIN (SELECT ROW("C 1", c2, c3, c4, c5, c6, c7, c8), "C 1" FROM "S 1"."T 1" WHERE ((("C 1" % 10) = 9))) s2(c1, c2) ON (((r1.c2 = s2.c2)))) FOR UPDATE OF r1
-> Hash Join
Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c8, ft2.ctid, ft1.*
Hash Cond: (ft2.c2 = ft1.c1)
***************
*** 4207,4220 **** DELETE FROM ft2 WHERE c1 % 10 = 5 RETURNING c1, c4;
EXPLAIN (verbose, costs off)
DELETE FROM ft2 USING ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 2; -- can't be pushed down
! QUERY PLAN
! -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Delete on public.ft2
Remote SQL: DELETE FROM "S 1"."T 1" WHERE ctid = $1
-> Foreign Scan
Output: ft2.ctid, ft1.*
Relations: (public.ft2) INNER JOIN (public.ft1)
! Remote SQL: SELECT r1.ctid, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1.c2 = r2."C 1")) AND (((r2."C 1" % 10) = 2)))) FOR UPDATE OF r1
-> Hash Join
Output: ft2.ctid, ft1.*
Hash Cond: (ft2.c2 = ft1.c1)
--- 4254,4267 ----
EXPLAIN (verbose, costs off)
DELETE FROM ft2 USING ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 2; -- can't be pushed down
! QUERY PLAN
! ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Delete on public.ft2
Remote SQL: DELETE FROM "S 1"."T 1" WHERE ctid = $1
-> Foreign Scan
Output: ft2.ctid, ft1.*
Relations: (public.ft2) INNER JOIN (public.ft1)
! Remote SQL: SELECT r1.ctid, s2.c1 FROM ("S 1"."T 1" r1 INNER JOIN (SELECT ROW("C 1", c2, c3, c4, c5, c6, c7, c8), "C 1" FROM "S 1"."T 1" WHERE ((("C 1" % 10) = 2))) s2(c1, c2) ON (((r1.c2 = s2.c2)))) FOR UPDATE OF r1
-> Hash Join
Output: ft2.ctid, ft1.*
Hash Cond: (ft2.c2 = ft1.c1)
*** a/contrib/postgres_fdw/postgres_fdw.c
--- b/contrib/postgres_fdw/postgres_fdw.c
***************
*** 28,33 ****
--- 28,34 ----
#include "optimizer/clauses.h"
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
+ #include "optimizer/placeholder.h"
#include "optimizer/planmain.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/var.h"
***************
*** 582,587 **** postgresGetForeignRelSize(PlannerInfo *root,
--- 583,633 ----
}
/*
+ * Detect whether expressions in the relation's reltarget are shippable
+ * and whether there are any non-Vars in those expressions.
+ *
+ * Note: whole-row Vars and system columns other than ctid and oid are
+ * treated like non-Vars. (See comments in postgres_fdw.h.)
+ *
+ * Note: if the relation is an appendrel child, it isn't in the main join
+ * tree, so those information is not used.
+ */
+ if (baserel->reloptkind == RELOPT_BASEREL)
+ {
+ bool reltarget_is_shippable = true;
+ bool reltarget_has_non_vars = false;
+
+ foreach(lc, baserel->reltarget->exprs)
+ {
+ Node *node = (Node *) lfirst(lc);
+
+ if (IsA(node, Var))
+ {
+ Var *var = (Var *) node;
+
+ if (var->varattno <= 0 &&
+ var->varattno != SelfItemPointerAttributeNumber &&
+ var->varattno != ObjectIdAttributeNumber)
+ reltarget_has_non_vars = true;
+ }
+ else if (IsA(node, PlaceHolderVar))
+ {
+ reltarget_has_non_vars = true;
+
+ if (!is_foreign_expr(root, baserel, (Expr *) node))
+ {
+ reltarget_is_shippable = false;
+ break;
+ }
+ }
+ else
+ elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
+ }
+ fpinfo->reltarget_is_shippable = reltarget_is_shippable;
+ fpinfo->reltarget_has_non_vars = reltarget_has_non_vars;
+ }
+
+ /*
* Compute the selectivity and cost of the local_conds, so we don't have
* to do it over again for each path. The best we can do for these
* conditions is to estimate selectivity on the basis of local statistics.
***************
*** 1199,1205 **** postgresGetForeignPlan(PlannerInfo *root,
local_exprs = fpinfo->local_conds;
/* Build the list of columns to be fetched from the foreign server. */
! fdw_scan_tlist = build_tlist_to_deparse(foreignrel);
/*
* Ensure that the outer plan produces a tuple whose descriptor
--- 1245,1251 ----
local_exprs = fpinfo->local_conds;
/* Build the list of columns to be fetched from the foreign server. */
! fdw_scan_tlist = build_tlist_to_deparse(root, foreignrel);
/*
* Ensure that the outer plan produces a tuple whose descriptor
***************
*** 2539,2545 **** estimate_path_cost_size(PlannerInfo *root,
/* Build the list of columns to be fetched from the foreign server. */
if (foreignrel->reloptkind == RELOPT_JOINREL ||
foreignrel->reloptkind == RELOPT_UPPER_REL)
! fdw_scan_tlist = build_tlist_to_deparse(foreignrel);
else
fdw_scan_tlist = NIL;
--- 2585,2591 ----
/* Build the list of columns to be fetched from the foreign server. */
if (foreignrel->reloptkind == RELOPT_JOINREL ||
foreignrel->reloptkind == RELOPT_UPPER_REL)
! fdw_scan_tlist = build_tlist_to_deparse(root, foreignrel);
else
fdw_scan_tlist = NIL;
***************
*** 4055,4060 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
--- 4101,4108 ----
ListCell *lc;
List *joinclauses;
List *otherclauses;
+ bool reltarget_is_shippable = true;
+ bool reltarget_has_non_vars = false;
/*
* We support pushing down INNER, LEFT, RIGHT and FULL OUTER joins.
***************
*** 4084,4089 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
--- 4132,4145 ----
if (fpinfo_o->local_conds || fpinfo_i->local_conds)
return false;
+ /*
+ * If the reltargets of joining relations are not shippable, those are
+ * required to be evaluated locally, so the join can not be pushed down.
+ */
+ if (!fpinfo_o->reltarget_is_shippable ||
+ !fpinfo_i->reltarget_is_shippable)
+ return false;
+
/* Separate restrict list into join quals and quals on join relation */
if (IS_OUTER_JOIN(jointype))
extract_actual_join_clauses(extra->restrictlist, &joinclauses, &otherclauses);
***************
*** 4109,4134 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
return false;
}
- /*
- * deparseExplicitTargetList() isn't smart enough to handle anything other
- * than a Var. In particular, if there's some PlaceHolderVar that would
- * need to be evaluated within this join tree (because there's an upper
- * reference to a quantity that may go to NULL as a result of an outer
- * join), then we can't try to push the join down because we'll fail when
- * we get to deparseExplicitTargetList(). However, a PlaceHolderVar that
- * needs to be evaluated *at the top* of this join tree is OK, because we
- * can do that locally after fetching the results from the remote side.
- */
- foreach(lc, root->placeholder_list)
- {
- PlaceHolderInfo *phinfo = lfirst(lc);
- Relids relids = joinrel->relids;
-
- if (bms_is_subset(phinfo->ph_eval_at, relids) &&
- bms_nonempty_difference(relids, phinfo->ph_eval_at))
- return false;
- }
-
/* Save the join clauses, for later use. */
fpinfo->joinclauses = joinclauses;
--- 4165,4170 ----
***************
*** 4185,4211 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
*
* The joining sides can not have local conditions, thus no need to test
* shippability of the clauses being pulled up.
*/
switch (jointype)
{
case JOIN_INNER:
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_i->remote_conds));
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_o->remote_conds));
break;
case JOIN_LEFT:
! fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
list_copy(fpinfo_i->remote_conds));
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_o->remote_conds));
break;
case JOIN_RIGHT:
! fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
list_copy(fpinfo_o->remote_conds));
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_i->remote_conds));
break;
--- 4221,4271 ----
*
* The joining sides can not have local conditions, thus no need to test
* shippability of the clauses being pulled up.
+ *
+ * If the joining relation has reltarget_has_non_vars=TRUE, that relation
+ * is deparsed as a subquery and the remote_conds of that relation is
+ * transformed into the WHERE clause of the subquery. So in that case,
+ * don't pull up the remote_conds into the joinclauses or remote_conds of
+ * this relation.
*/
switch (jointype)
{
case JOIN_INNER:
! if (fpinfo_i->reltarget_has_non_vars)
! fpinfo->make_innerrel_subquery = true;
! else
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_i->remote_conds));
! if (fpinfo_o->reltarget_has_non_vars)
! fpinfo->make_outerrel_subquery = true;
! else
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_o->remote_conds));
break;
case JOIN_LEFT:
! if (fpinfo_i->reltarget_has_non_vars)
! fpinfo->make_innerrel_subquery = true;
! else
! fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
list_copy(fpinfo_i->remote_conds));
! if (fpinfo_o->reltarget_has_non_vars)
! fpinfo->make_outerrel_subquery = true;
! else
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_o->remote_conds));
break;
case JOIN_RIGHT:
! if (fpinfo_o->reltarget_has_non_vars)
! fpinfo->make_outerrel_subquery = true;
! else
! fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
list_copy(fpinfo_o->remote_conds));
! if (fpinfo_i->reltarget_has_non_vars)
! fpinfo->make_innerrel_subquery = true;
! else
! fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
list_copy(fpinfo_i->remote_conds));
break;
***************
*** 4215,4236 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
* In this case, if any of the joining relations has conditions,
* we need to deparse that relation as a subquery so that
* conditions can be evaluated before the join. Remember it in
! * the fpinfo so that deparser can take appropriate action. We
! * also save the relids of that relation that is covered by the
! * subquery for later use of deparser.
*/
! if (fpinfo_o->remote_conds)
! {
fpinfo->make_outerrel_subquery = true;
! fpinfo->subquery_rels = bms_add_members(fpinfo->subquery_rels,
! outerrel->relids);
! }
! if (fpinfo_i->remote_conds)
! {
fpinfo->make_innerrel_subquery = true;
- fpinfo->subquery_rels = bms_add_members(fpinfo->subquery_rels,
- innerrel->relids);
- }
break;
default:
--- 4275,4286 ----
* In this case, if any of the joining relations has conditions,
* we need to deparse that relation as a subquery so that
* conditions can be evaluated before the join. Remember it in
! * the fpinfo so that deparser can take appropriate action.
*/
! if (fpinfo_o->reltarget_has_non_vars || fpinfo_o->remote_conds)
fpinfo->make_outerrel_subquery = true;
! if (fpinfo_i->reltarget_has_non_vars || fpinfo_i->remote_conds)
fpinfo->make_innerrel_subquery = true;
break;
default:
***************
*** 4239,4244 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
--- 4289,4305 ----
}
/*
+ * If the joining relation is deparsed as a subquery, save the relids of
+ * that relation covered by the subquery for later use of deparser.
+ */
+ if (fpinfo->make_outerrel_subquery)
+ fpinfo->subquery_rels = bms_add_members(fpinfo->subquery_rels,
+ outerrel->relids);
+ if (fpinfo->make_innerrel_subquery)
+ fpinfo->subquery_rels = bms_add_members(fpinfo->subquery_rels,
+ innerrel->relids);
+
+ /*
* For an inner join, all restrictions can be treated alike. Treating the
* pushed down conditions as join conditions allows a top level full outer
* join to be deparsed without requiring subqueries.
***************
*** 4254,4259 **** foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
--- 4315,4358 ----
fpinfo->pushdown_safe = true;
/*
+ * Detect whether expressions in the relation's reltarget are shippable
+ * and whether there are any non-Vars in those expressions.
+ *
+ * Note: whole-row Vars and system columns other than ctid and oid of a
+ * base relation (if any) are handled as output columns of a lower
+ * subquery by deparser. So no need to be careful about those columns.
+ */
+ foreach(lc, joinrel->reltarget->exprs)
+ {
+ Node *node = (Node *) lfirst(lc);
+
+ if (IsA(node, Var))
+ continue;
+ if (IsA(node, PlaceHolderVar))
+ {
+ PlaceHolderVar *phv = (PlaceHolderVar *) node;
+ PlaceHolderInfo *phinfo = find_placeholder_info(root, phv, false);
+
+ /* Ignore the PHV if it has bubbled up from an either input. */
+ if (bms_is_subset(phinfo->ph_eval_at, outerrel->relids) ||
+ bms_is_subset(phinfo->ph_eval_at, innerrel->relids))
+ continue;
+
+ reltarget_has_non_vars = true;
+
+ if (!is_foreign_expr(root, joinrel, (Expr *) node))
+ {
+ reltarget_is_shippable = false;
+ break;
+ }
+ }
+ else
+ elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
+ }
+ fpinfo->reltarget_is_shippable = reltarget_is_shippable;
+ fpinfo->reltarget_has_non_vars = reltarget_has_non_vars;
+
+ /*
* If user is willing to estimate cost for a scan of either of the joining
* relations using EXPLAIN, he intends to estimate scans on that relation
* more accurately. Then, it makes sense to estimate the cost the join
*** a/contrib/postgres_fdw/postgres_fdw.h
--- b/contrib/postgres_fdw/postgres_fdw.h
***************
*** 33,38 **** typedef struct PgFdwRelationInfo
--- 33,61 ----
bool pushdown_safe;
/*
+ * Flags on the reltarget of the relation.
+ *
+ * If each expression in the relation's reltarget is shippable (i.e.,
+ * computable on the remote side), we set reltarget_is_shippalbe to TRUE.
+ * The flag is used to detect whether the relation can be joined with any
+ * other foreign table (or join) on the remote server. Note that Vars in
+ * the reltarget are shippable, so if any PHVs in the reltarget are
+ * shippable, then the flag is set TRUE. Also, if the reltarget contains
+ * any PHVs, we set reltarget_has_non_vars to TRUE. In that case, if the
+ * relation is joined with any other foreign table on the remote server,
+ * the relation is deparsed as a subquery emitting the PHVs when creating
+ * a remote query. Note that whole-row Vars and system columns other than
+ * ctid and oid in the reltarget of a base relation are treated like PHVs,
+ * because we fetch the whole-row Vars as ROW() expressions and the system
+ * columns as 0, except for tableoid, in which case we fetch it as a valid
+ * value for the local table OID, and because the base table could be
+ * beneath an outer join, in which case those columns must go to NULL
+ * whenever the rest of the row does.
+ */
+ bool reltarget_is_shippable; /* are reltarget exprs shippable? */
+ bool reltarget_has_non_vars; /* are there any non-Var exprs? */
+
+ /*
* Restriction clauses, divided into safe and unsafe to pushdown subsets.
*
* For a base foreign relation this is a list of clauses along-with
***************
*** 171,177 **** extern void deparseAnalyzeSql(StringInfo buf, Relation rel,
List **retrieved_attrs);
extern void deparseStringLiteral(StringInfo buf, const char *val);
extern Expr *find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel);
! extern List *build_tlist_to_deparse(RelOptInfo *foreignrel);
extern void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root,
RelOptInfo *foreignrel, List *tlist,
List *remote_conds, List *pathkeys,
--- 194,200 ----
List **retrieved_attrs);
extern void deparseStringLiteral(StringInfo buf, const char *val);
extern Expr *find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel);
! extern List *build_tlist_to_deparse(PlannerInfo *root, RelOptInfo *foreignrel);
extern void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root,
RelOptInfo *foreignrel, List *tlist,
List *remote_conds, List *pathkeys,
*** a/contrib/postgres_fdw/sql/postgres_fdw.sql
--- b/contrib/postgres_fdw/sql/postgres_fdw.sql
***************
*** 503,519 **** EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM ft1 t2, ft2 t3 WHERE t2.c1 = t3.c1 AND t2.c2 = t1.c2) q ORDER BY t1."C 1" OFFSET 10 LIMIT 10;
SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM ft1 t2, ft2 t3 WHERE t2.c1 = t3.c1 AND t2.c2 = t1.c2) q ORDER BY t1."C 1" OFFSET 10 LIMIT 10;
! -- non-Var items in targelist of the nullable rel of a join preventing
! -- push-down in some cases
! -- unable to push {ft1, ft2}
EXPLAIN (VERBOSE, COSTS OFF)
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
-
- -- ok to push {ft1, ft2} but not {ft1, ft2, ft4}
EXPLAIN (VERBOSE, COSTS OFF)
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
-- join with nullable side with some columns with null values
UPDATE ft5 SET c3 = null where c1 % 9 = 0;
--- 503,524 ----
SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM ft1 t2, ft2 t3 WHERE t2.c1 = t3.c1 AND t2.c2 = t1.c2) q ORDER BY t1."C 1" OFFSET 10 LIMIT 10;
SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM ft1 t2, ft2 t3 WHERE t2.c1 = t3.c1 AND t2.c2 = t1.c2) q ORDER BY t1."C 1" OFFSET 10 LIMIT 10;
! -- check join pushdown in situations where PHVs are involved
EXPLAIN (VERBOSE, COSTS OFF)
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
SELECT q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15;
EXPLAIN (VERBOSE, COSTS OFF)
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
SELECT ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15;
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT ft2.c1, q2.* FROM ft2 LEFT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2) WHERE ft2.c1 BETWEEN 10 AND 15;
+ SELECT ft2.c1, q2.* FROM ft2 LEFT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2) WHERE ft2.c1 BETWEEN 10 AND 15;
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT ft2.c1, q2.* FROM ft2 RIGHT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2);
+ SELECT ft2.c1, q2.* FROM ft2 RIGHT JOIN (SELECT 13, q.a, ft2.c1 FROM (SELECT 13 FROM ft1 WHERE c1 = 13) q(a) RIGHT JOIN ft2 ON (q.a = ft2.c1) WHERE ft2.c1 BETWEEN 10 AND 15) q2(a2, b2, c2) ON (ft2.c1 = q2.a2);
+ EXPLAIN (VERBOSE, COSTS OFF)
+ SELECT ft4.c1, q2.* FROM ft4 LEFT JOIN (SELECT (q.a IS NOT NULL), ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15) q2(a2, b2, c2, d2, e2) ON (ft4.c1 = q2.b2) WHERE ft4.c1 BETWEEN 10 AND 15;
+ SELECT ft4.c1, q2.* FROM ft4 LEFT JOIN (SELECT (q.a IS NOT NULL), ft4.c1, q.* FROM ft4 LEFT JOIN (SELECT 13, ft1.c1, ft2.c1 FROM ft1 RIGHT JOIN ft2 ON (ft1.c1 = ft2.c1) WHERE ft1.c1 = 12) q(a, b, c) ON (ft4.c1 = q.b) WHERE ft4.c1 BETWEEN 10 AND 15) q2(a2, b2, c2, d2, e2) ON (ft4.c1 = q2.b2) WHERE ft4.c1 BETWEEN 10 AND 15;
-- join with nullable side with some columns with null values
UPDATE ft5 SET c3 = null where c1 % 9 = 0;
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
