Hi,
Attached is the updated patch.
On Mon, 16 Oct 2017 10:07:48 +0900 (JST)
Tatsuo Ishii <is...@sraoss.co.jp> wrote:
> >> > It would be nice if the message would be something like:
> >> >
> >> > DETAIL: Views that return aggregate functions are not lockable
> You could add a flag to view_query_is_auto_updatable() to switch the
> message between
>
> DETAIL: Views that return aggregate functions are not automatically
> updatable.
>
> and
>
> DETAIL: Views that return aggregate functions are not lockable
I didn't want to change the interface of view_query_is_auto_updatable()
because this might be called from other third-patry software, so I renamed
this function to view_query_is_auto_updatable_or_lockable() and added the flag
to this. I created view_query_is_auto_updatable() as a wrapper of this function.
I also made view_query_is_lockable() that returns a other message than
view_query_is_auto_updatable().
> On Tue, 17 Oct 2017 11:59:05 +0900 (JST)
> Tatsuo Ishii <is...@sraoss.co.jp> wrote:
> > 1) Leave as it is (ignore tables appearing in a subquery)
> >
> > 2) Lock all tables including in a subquery
> >
> > 3) Check subquery in the view
> > So it seem #1 is the most reasonable way to deal with the problem
> > assuming that it's user's responsibility to take appropriate locks on
> > the tables in the subquery.
I adopted #1 and I didn't change anything about this.
Regards,
--
Yugo Nagata <nag...@sraoss.co.jp>
diff --git a/src/backend/commands/lockcmds.c b/src/backend/commands/lockcmds.c
index 9fe9e02..80e00f7 100644
--- a/src/backend/commands/lockcmds.c
+++ b/src/backend/commands/lockcmds.c
@@ -19,15 +19,20 @@
#include "commands/lockcmds.h"
#include "miscadmin.h"
#include "parser/parse_clause.h"
+#include "parser/parsetree.h"
#include "storage/lmgr.h"
#include "utils/acl.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
+#include "rewrite/rewriteHandler.h"
+#include "access/heapam.h"
-static void LockTableRecurse(Oid reloid, LOCKMODE lockmode, bool nowait);
-static AclResult LockTableAclCheck(Oid relid, LOCKMODE lockmode);
+static void LockTableRecurse(Oid reloid, LOCKMODE lockmode, bool nowait, Oid userid);
+static AclResult LockTableAclCheck(Oid relid, LOCKMODE lockmode, Oid userid);
static void RangeVarCallbackForLockTable(const RangeVar *rv, Oid relid,
Oid oldrelid, void *arg);
+static void LockViewRecurse(Oid reloid, Oid root_reloid, LOCKMODE lockmode, bool nowait);
+static void LockViewCheck(Relation view, Query *viewquery);
/*
* LOCK TABLE
@@ -62,8 +67,10 @@ LockTableCommand(LockStmt *lockstmt)
RangeVarCallbackForLockTable,
(void *) &lockstmt->mode);
- if (recurse)
- LockTableRecurse(reloid, lockstmt->mode, lockstmt->nowait);
+ if (get_rel_relkind(reloid) == RELKIND_VIEW)
+ LockViewRecurse(reloid, reloid, lockstmt->mode, lockstmt->nowait);
+ else if (recurse)
+ LockTableRecurse(reloid, lockstmt->mode, lockstmt->nowait, GetUserId());
}
}
@@ -86,15 +93,17 @@ RangeVarCallbackForLockTable(const RangeVar *rv, Oid relid, Oid oldrelid,
return; /* woops, concurrently dropped; no permissions
* check */
- /* Currently, we only allow plain tables to be locked */
- if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE)
+
+ /* Currently, we only allow plain tables or auto-updatable views to be locked */
+ if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE &&
+ relkind != RELKIND_VIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
- errmsg("\"%s\" is not a table",
+ errmsg("\"%s\" is not a table or view",
rv->relname)));
/* Check permissions. */
- aclresult = LockTableAclCheck(relid, lockmode);
+ aclresult = LockTableAclCheck(relid, lockmode, GetUserId());
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_CLASS, rv->relname);
}
@@ -107,7 +116,7 @@ RangeVarCallbackForLockTable(const RangeVar *rv, Oid relid, Oid oldrelid,
* multiply-inheriting children more than once, but that's no problem.
*/
static void
-LockTableRecurse(Oid reloid, LOCKMODE lockmode, bool nowait)
+LockTableRecurse(Oid reloid, LOCKMODE lockmode, bool nowait, Oid userid)
{
List *children;
ListCell *lc;
@@ -120,7 +129,7 @@ LockTableRecurse(Oid reloid, LOCKMODE lockmode, bool nowait)
AclResult aclresult;
/* Check permissions before acquiring the lock. */
- aclresult = LockTableAclCheck(childreloid, lockmode);
+ aclresult = LockTableAclCheck(childreloid, lockmode, userid);
if (aclresult != ACLCHECK_OK)
{
char *relname = get_rel_name(childreloid);
@@ -157,15 +166,82 @@ LockTableRecurse(Oid reloid, LOCKMODE lockmode, bool nowait)
continue;
}
- LockTableRecurse(childreloid, lockmode, nowait);
+ LockTableRecurse(childreloid, lockmode, nowait, userid);
}
}
/*
+ * Apply LOCK TABLE recursively over a view
+ */
+static void
+LockViewRecurse(Oid reloid, Oid root_reloid, LOCKMODE lockmode, bool nowait)
+{
+ Relation view;
+ Query *viewquery;
+ RangeTblRef *rtr;
+ RangeTblEntry *base_rte;
+ Oid baseoid;
+ AclResult aclresult;
+ char *relname;
+ char relkind;
+
+ view = heap_open(reloid, NoLock);
+ viewquery = get_view_query(view);
+
+ /* Check whether the view is lockable */
+ LockViewCheck(view, viewquery);
+
+ heap_close(view, NoLock);
+
+ Assert(list_length(viewquery->jointree->fromlist) == 1);
+ rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
+ base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
+ Assert(base_rte->rtekind == RTE_RELATION);
+
+ baseoid = base_rte->relid;
+ relname = get_rel_name(baseoid);
+ relkind = get_rel_relkind(baseoid);
+
+ /* Currently, we only allow plain tables or auto-updatable views to be locked */
+ if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE &&
+ relkind != RELKIND_VIEW)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("\"%s\" is not a table or view",
+ relname)));
+
+ /* Check infinite recursion in the view definition */
+ if (baseoid == root_reloid)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("infinite recursion detected in rules for relation \"%s\"",
+ get_rel_name(root_reloid))));
+
+ /* Check permissions with the view owner's priviledge. */
+ aclresult = LockTableAclCheck(baseoid, lockmode, view->rd_rel->relowner);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, ACL_KIND_CLASS, relname);
+
+ /* We have enough rights to lock the relation; do so. */
+ if (!nowait)
+ LockRelationOid(baseoid, lockmode);
+ else if (!ConditionalLockRelationOid(baseoid, lockmode))
+ ereport(ERROR,
+ (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
+ errmsg("could not obtain lock on relation \"%s\"",
+ relname)));
+
+ if (relkind == RELKIND_VIEW)
+ LockViewRecurse(baseoid, root_reloid, lockmode, nowait);
+ else if (base_rte->inh)
+ LockTableRecurse(baseoid, lockmode, nowait, view->rd_rel->relowner);
+}
+
+/*
* Check whether the current user is permitted to lock this relation.
*/
static AclResult
-LockTableAclCheck(Oid reloid, LOCKMODE lockmode)
+LockTableAclCheck(Oid reloid, LOCKMODE lockmode, Oid userid)
{
AclResult aclresult;
AclMode aclmask;
@@ -178,7 +254,50 @@ LockTableAclCheck(Oid reloid, LOCKMODE lockmode)
else
aclmask = ACL_UPDATE | ACL_DELETE | ACL_TRUNCATE;
- aclresult = pg_class_aclcheck(reloid, GetUserId(), aclmask);
+ aclresult = pg_class_aclcheck(reloid, userid, aclmask);
return aclresult;
}
+
+/*
+ * Check whether the view is lockable.
+ *
+ * Currently, only auto-updatable views can be locked, that is,
+ * views whose definition are simple and that doesn't have
+ * instead of rules or triggers are lockable.
+ */
+static void
+LockViewCheck(Relation view, Query *viewquery)
+{
+ const char *relname = RelationGetRelationName(view);
+ const char *lockable_detail;
+ int i;
+
+ lockable_detail = view_query_is_lockable(viewquery);
+ if (lockable_detail)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot lock view \"%s\"", relname),
+ errdetail_internal("%s", _(lockable_detail))));
+
+
+ /* Confirm the view doesn't have instead of rules */
+ for (i=0; i<view->rd_rules->numLocks; i++)
+ {
+ if (view->rd_rules->rules[i]->isInstead && view->rd_rules->rules[i]->event != CMD_SELECT)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot lock view \"%s\"", relname),
+ errdetail_internal("views that have an INSTEAD OF rule are not lockable")));
+ }
+
+ /* Confirm the view doesn't have instead of triggers */
+ if (view->trigdesc &&
+ (view->trigdesc->trig_insert_instead_row ||
+ view->trigdesc->trig_update_instead_row ||
+ view->trigdesc->trig_delete_instead_row))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot lock view \"%s\"", relname),
+ errdetail_internal("views that have an INSTEAD OF trigger are not lockable")));
+}
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index e93552a..da7fce0 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -2236,20 +2236,23 @@ view_col_is_auto_updatable(RangeTblRef *rtr, TargetEntry *tle)
/*
- * view_query_is_auto_updatable - test whether the specified view definition
- * represents an auto-updatable view. Returns NULL (if the view can be updated)
- * or a message string giving the reason that it cannot be.
+ * view_query_is_auto_updatable_or_lockable - test whether the specified view
+ * definition represents an auto-updatable view. Returns NULL (if the view can
+ * be updated) or a message string giving the reason that it cannot be.
*
* If check_cols is true, the view is required to have at least one updatable
* column (necessary for INSERT/UPDATE). Otherwise the view's columns are not
* checked for updatability. See also view_cols_are_auto_updatable.
*
+ * If for_lock is true, the returned message describes the reason that it
+ * cannot be lockable rather than auto-updatable.
+ *
* Note that the checks performed here are only based on the view definition.
* We do not check whether any base relations referred to by the view are
* updatable.
*/
-const char *
-view_query_is_auto_updatable(Query *viewquery, bool check_cols)
+static const char *
+view_query_is_auto_updatable_or_lockable(Query *viewquery, bool check_cols, bool for_lock)
{
RangeTblRef *rtr;
RangeTblEntry *base_rte;
@@ -2287,22 +2290,34 @@ view_query_is_auto_updatable(Query *viewquery, bool check_cols)
*----------
*/
if (viewquery->distinctClause != NIL)
- return gettext_noop("Views containing DISTINCT are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views containing DISTINCT are not automatically updatable.") :
+ gettext_noop("Views containing DISTINCT are not lockable."));
if (viewquery->groupClause != NIL || viewquery->groupingSets)
- return gettext_noop("Views containing GROUP BY are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views containing GROUP BY are not automatically updatable.") :
+ gettext_noop("Views containing GROUP BY are not lockable."));
if (viewquery->havingQual != NULL)
- return gettext_noop("Views containing HAVING are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views containing HAVING are not automatically updatable.") :
+ gettext_noop("Views containing HAVING are not lockable."));
if (viewquery->setOperations != NULL)
- return gettext_noop("Views containing UNION, INTERSECT, or EXCEPT are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views containing UNION, INTERSECT, or EXCEPT are not automatically updatable.") :
+ gettext_noop("Views containing UNION, INTERSECT, or EXCEPT are not lockable."));
if (viewquery->cteList != NIL)
- return gettext_noop("Views containing WITH are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views containing WITH are not automatically updatable.") :
+ gettext_noop("Views containing WITH are not lockable."));
if (viewquery->limitOffset != NULL || viewquery->limitCount != NULL)
- return gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.") :
+ gettext_noop("Views containing LIMIT or OFFSET are not lockable."));
/*
* We must not allow window functions or set returning functions in the
@@ -2314,24 +2329,34 @@ view_query_is_auto_updatable(Query *viewquery, bool check_cols)
* unique row in the underlying base relation.
*/
if (viewquery->hasAggs)
- return gettext_noop("Views that return aggregate functions are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views that return aggregate functions are not automatically updatable.") :
+ gettext_noop("Views that return aggregate functions are not lockable."));
if (viewquery->hasWindowFuncs)
- return gettext_noop("Views that return window functions are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views that return window functions are not automatically updatable.") :
+ gettext_noop("Views that return window functions are not lockable."));
if (viewquery->hasTargetSRFs)
- return gettext_noop("Views that return set-returning functions are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views that return set-returning functions are not automatically updatable.") :
+ gettext_noop("Views that return set-returning functions are not lockable."));
/*
* The view query should select from a single base relation, which must be
* a table or another view.
*/
if (list_length(viewquery->jointree->fromlist) != 1)
- return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views that do not select from a single table or view are not automatically updatable.") :
+ gettext_noop("Views that do not select from a single table or view are not lockable."));
rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
if (!IsA(rtr, RangeTblRef))
- return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views that do not select from a single table or view are not automatically updatable.") :
+ gettext_noop("Views that do not select from a single table or view are not lockable."));
base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
if (base_rte->rtekind != RTE_RELATION ||
@@ -2339,10 +2364,14 @@ view_query_is_auto_updatable(Query *viewquery, bool check_cols)
base_rte->relkind != RELKIND_FOREIGN_TABLE &&
base_rte->relkind != RELKIND_VIEW &&
base_rte->relkind != RELKIND_PARTITIONED_TABLE))
- return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views that do not select from a single table or view are not automatically updatable.") :
+ gettext_noop("Views that do not select from a single table or view are not lockable."));
if (base_rte->tablesample)
- return gettext_noop("Views containing TABLESAMPLE are not automatically updatable.");
+ return (!for_lock ?
+ gettext_noop("Views containing TABLESAMPLE are not automatically updatable.") :
+ gettext_noop("Views containing TABLESAMPLE are not lockable."));
/*
* Check that the view has at least one updatable column. This is required
@@ -2374,6 +2403,29 @@ view_query_is_auto_updatable(Query *viewquery, bool check_cols)
/*
+ * view_query_is_auto_updatable - a simple wrapper function of
+ * view_query_is_auto_updatable_or_lockable
+ */
+const char *
+view_query_is_auto_updatable(Query *viewquery, bool check_cols)
+{
+ return view_query_is_auto_updatable_or_lockable(viewquery, check_cols, false);
+}
+
+/*
+ * view_query_is_lockable - a wrapper function of
+ * view_query_is_auto_updatable_or_lockable to check whether a given view is
+ * lockable. Returns NULL (if the view can be locked) or a message string
+ * giving the reason that it cannot be.
+ */
+const char *
+view_query_is_lockable(Query *viewquery)
+{
+ return view_query_is_auto_updatable_or_lockable(viewquery, false, true);
+}
+
+
+/*
* view_cols_are_auto_updatable - test whether all of the required columns of
* an auto-updatable view are actually updatable. Returns NULL (if all the
* required columns can be updated) or a message string giving the reason that
diff --git a/src/include/rewrite/rewriteHandler.h b/src/include/rewrite/rewriteHandler.h
index 86ae571..edd6693 100644
--- a/src/include/rewrite/rewriteHandler.h
+++ b/src/include/rewrite/rewriteHandler.h
@@ -29,6 +29,7 @@ extern void rewriteTargetListUD(Query *parsetree, RangeTblEntry *target_rte,
extern Query *get_view_query(Relation view);
extern const char *view_query_is_auto_updatable(Query *viewquery,
bool check_cols);
+extern const char *view_query_is_lockable(Query *viewquery);
extern int relation_is_updatable(Oid reloid,
bool include_triggers,
Bitmapset *include_cols);
diff --git a/src/test/regress/expected/lock.out b/src/test/regress/expected/lock.out
index fd27344..8c1f587 100644
--- a/src/test/regress/expected/lock.out
+++ b/src/test/regress/expected/lock.out
@@ -5,7 +5,9 @@
CREATE SCHEMA lock_schema1;
SET search_path = lock_schema1;
CREATE TABLE lock_tbl1 (a BIGINT);
-CREATE VIEW lock_view1 AS SELECT 1;
+CREATE VIEW lock_view1 AS SELECT * FROM lock_tbl1;
+CREATE VIEW lock_view2 AS SELECT count(*) FROM lock_tbl1;
+CREATE VIEW lock_view3 AS SELECT 1;
CREATE ROLE regress_rol_lock1;
ALTER ROLE regress_rol_lock1 SET search_path = lock_schema1;
GRANT USAGE ON SCHEMA lock_schema1 TO regress_rol_lock1;
@@ -30,8 +32,17 @@ LOCK TABLE lock_tbl1 IN SHARE MODE NOWAIT;
LOCK TABLE lock_tbl1 IN SHARE ROW EXCLUSIVE MODE NOWAIT;
LOCK TABLE lock_tbl1 IN EXCLUSIVE MODE NOWAIT;
LOCK TABLE lock_tbl1 IN ACCESS EXCLUSIVE MODE NOWAIT;
-LOCK TABLE lock_view1 IN EXCLUSIVE MODE; -- Will fail; can't lock a non-table
-ERROR: "lock_view1" is not a table
+LOCK TABLE lock_view1 IN EXCLUSIVE MODE; -- OK; can lock an autoupdatable view
+ROLLBACK;
+BEGIN TRANSACTION;
+LOCK TABLE lock_view2 IN EXCLUSIVE MODE; -- Will fail; can't lock a non-autoupdatable view
+ERROR: cannot lock view "lock_view2"
+DETAIL: Views that return aggregate functions are not lockable.
+ROLLBACK;
+BEGIN TRANSACTION;
+LOCK TABLE lock_view3 IN EXCLUSIVE MODE; -- Will fail; can't lock a non-autoupdatable view
+ERROR: cannot lock view "lock_view3"
+DETAIL: Views that do not select from a single table or view are not lockable.
ROLLBACK;
-- Verify that we can lock a table with inheritance children.
CREATE TABLE lock_tbl2 (b BIGINT) INHERITS (lock_tbl1);
@@ -55,6 +66,8 @@ RESET ROLE;
-- Clean up
--
DROP VIEW lock_view1;
+DROP VIEW lock_view2;
+DROP VIEW lock_view3;
DROP TABLE lock_tbl3;
DROP TABLE lock_tbl2;
DROP TABLE lock_tbl1;
diff --git a/src/test/regress/sql/lock.sql b/src/test/regress/sql/lock.sql
index 567e8bc..d8e97d7 100644
--- a/src/test/regress/sql/lock.sql
+++ b/src/test/regress/sql/lock.sql
@@ -6,7 +6,9 @@
CREATE SCHEMA lock_schema1;
SET search_path = lock_schema1;
CREATE TABLE lock_tbl1 (a BIGINT);
-CREATE VIEW lock_view1 AS SELECT 1;
+CREATE VIEW lock_view1 AS SELECT * FROM lock_tbl1;
+CREATE VIEW lock_view2 AS SELECT count(*) FROM lock_tbl1;
+CREATE VIEW lock_view3 AS SELECT 1;
CREATE ROLE regress_rol_lock1;
ALTER ROLE regress_rol_lock1 SET search_path = lock_schema1;
GRANT USAGE ON SCHEMA lock_schema1 TO regress_rol_lock1;
@@ -33,7 +35,13 @@ LOCK TABLE lock_tbl1 IN SHARE MODE NOWAIT;
LOCK TABLE lock_tbl1 IN SHARE ROW EXCLUSIVE MODE NOWAIT;
LOCK TABLE lock_tbl1 IN EXCLUSIVE MODE NOWAIT;
LOCK TABLE lock_tbl1 IN ACCESS EXCLUSIVE MODE NOWAIT;
-LOCK TABLE lock_view1 IN EXCLUSIVE MODE; -- Will fail; can't lock a non-table
+LOCK TABLE lock_view1 IN EXCLUSIVE MODE; -- OK; can lock an autoupdatable view
+ROLLBACK;
+BEGIN TRANSACTION;
+LOCK TABLE lock_view2 IN EXCLUSIVE MODE; -- Will fail; can't lock a non-autoupdatable view
+ROLLBACK;
+BEGIN TRANSACTION;
+LOCK TABLE lock_view3 IN EXCLUSIVE MODE; -- Will fail; can't lock a non-autoupdatable view
ROLLBACK;
-- Verify that we can lock a table with inheritance children.
@@ -59,6 +67,8 @@ RESET ROLE;
-- Clean up
--
DROP VIEW lock_view1;
+DROP VIEW lock_view2;
+DROP VIEW lock_view3;
DROP TABLE lock_tbl3;
DROP TABLE lock_tbl2;
DROP TABLE lock_tbl1;
