Changeset: bec9777bc6ca for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/bec9777bc6ca
Modified Files:
sql/include/sql_relation.h
sql/server/rel_optimize_sel.c
Branch: default
Log Message:
implemented more efficient join order algorithm
diffs (294 lines):
diff --git a/sql/include/sql_relation.h b/sql/include/sql_relation.h
--- a/sql/include/sql_relation.h
+++ b/sql/include/sql_relation.h
@@ -46,7 +46,8 @@ typedef struct expression {
void *l;
void *r;
void *f; /* func's and aggr's, also e_cmp may have have 2
arguments */
- unsigned int flag; /* cmp types, PSM types/level */
+ unsigned short flag; /* cmp types, PSM types/level */
+ unsigned short tmp;
unsigned int
card:2, /* card (0 truth value!) (1 atoms) (2 aggr) (3 multi
value) */
freevar:4, /* free variable, ie binds to the upper dependent join
*/
diff --git a/sql/server/rel_optimize_sel.c b/sql/server/rel_optimize_sel.c
--- a/sql/server/rel_optimize_sel.c
+++ b/sql/server/rel_optimize_sel.c
@@ -1714,12 +1714,6 @@ joinexp_col(sql_exp *e, sql_rel *r)
return NULL;
}
-static int
-rel_has_exp2(sql_rel *r, sql_exp *e)
-{
- return rel_has_exp(r, e, false);
-}
-
static sql_column *
table_colexp(sql_exp *e, sql_rel *r)
{
@@ -2033,28 +2027,101 @@ find_fk( mvc *sql, list *rels, list *exp
return sdje;
}
+static int
+rels_find_one_rel( sql_rel **rels, int nr, sql_exp *e)
+{
+ int fnd = 0;
+
+ for(int i = 1; i<=nr; i++) {
+ if (rel_has_exp(rels[i], e, false) == 0) {
+ if (fnd)
+ return 0;
+ fnd = i;
+ }
+ }
+ return fnd;
+}
+
+/* TODO move popcount and popcount64 into gdk_*.h, used in gdk_cand, strimps
and here */
+static inline int
+popcount64(uint64_t x)
+{
+#if defined(__GNUC__)
+ return (uint32_t) __builtin_popcountll(x);
+#elif defined(_MSC_VER)
+ return (uint32_t) __popcnt64(x);
+#else
+ x = (x & 0x5555555555555555ULL) + ((x >> 1) & 0x5555555555555555ULL);
+ x = (x & 0x3333333333333333ULL) + ((x >> 2) & 0x3333333333333333ULL);
+ x = (x & 0x0F0F0F0F0F0F0F0FULL) + ((x >> 4) & 0x0F0F0F0F0F0F0F0FULL);
+ return (x * 0x0101010101010101ULL) >> 56;
+#endif
+}
+
static sql_rel *
order_joins(visitor *v, list *rels, list *exps)
{
sql_rel *top = NULL, *l = NULL, *r = NULL;
sql_exp *cje;
node *djn;
- list *sdje, *n_rels = sa_list(v->sql->sa);
+ list *sdje, *n_rels = NULL;
int fnd = 0;
unsigned int rsingle;
+ int direct = 1;
/* find foreign keys and reorder the expressions on reducing quality */
sdje = find_fk(v->sql, rels, exps);
+ for(djn = sdje->h; djn; djn = djn->next ) {
+ sql_exp *e = djn->data;
+ list_remove_data(exps, NULL, e);
+ }
if (list_length(rels) > 2 && mvc_debug_on(v->sql, 256)) {
- for(djn = sdje->h; djn; djn = djn->next ) {
- sql_exp *e = djn->data;
- list_remove_data(exps, NULL, e);
- }
top = rel_planner(v->sql, rels, sdje, exps);
return top;
}
+ int nr_exps = list_length(sdje), nr_rels = list_length(rels), ci = 1;
+ if (nr_rels > 64) {
+ direct = 0;
+ n_rels = sa_list(v->sql->ta);
+ }
+ sql_rel **rels_a = SA_NEW_ARRAY(v->sql->ta, sql_rel*, nr_rels+1); /*
don't use slot 0 */
+ rels_a[0] = NULL;
+ for (node *n = rels->h; n; n = n->next, ci++) {
+ rels_a[ci] = n->data;
+ }
+ ulng *h = SA_NEW_ARRAY(v->sql->ta, ulng, nr_exps), rel_mask = 0;
/* bit field (for > 64 its an imprint) */
+ uint16_t *r1 = SA_NEW_ARRAY(v->sql->ta, uint16_t, nr_exps);
+ uint16_t *r2 = SA_NEW_ARRAY(v->sql->ta, uint16_t, nr_exps);
+ /* change r3 into rest list's */
+ int *r3 = SA_NEW_ARRAY(v->sql->ta, int, nr_exps);
+
+ ci = 0;
+ for (node *n = sdje->h; n; n = n->next, ci++) {
+ sql_exp *cje = n->data;
+
+ h[ci] = r1[ci] = r2[ci] = 0;
+ r3[ci] = 0;
+ /* h[ci] = exp_find_rels(cje, rels) */
+ if (cje->type != e_cmp || is_complex_exp(cje->flag) ||
!find_prop(cje->p, PROP_HASHCOL) ||
+ (cje->type == e_cmp && cje->f == NULL)) {
+ cje->tmp = ci;
+ r1[ci] = rels_find_one_rel(rels_a, nr_rels, cje->l);
+ r2[ci] = rels_find_one_rel(rels_a, nr_rels, cje->r);
+ if (r1[ci])
+ h[ci] |= 1L<<((r1[ci]-1)%64);
+ if (r2[ci])
+ h[ci] |= 1L<<((r2[ci]-1)%64);
+ if (cje->f) {
+ r3[ci] = rels_find_one_rel(rels_a, nr_rels,
cje->f);
+ if (r3[ci] == r2[ci])
+ r3[ci] = 0;
+ if (r3[ci])
+ h[ci] |= 1L<<((r3[ci]-1)%64);
+ }
+ }
+ }
/* open problem, some expressions use more than 2 relations */
/* For example a.x = b.y * c.z; */
if (list_length(rels) >= 2 && sdje->h) {
@@ -2066,22 +2133,26 @@ order_joins(visitor *v, list *rels, list
/* complex expressions may touch multiple base tables
* Should be pushed up to extra selection.
* */
+ if (0 && popcount64(h[cje->tmp]) > 2)
+ assert(0);
if (cje->type != e_cmp || is_complex_exp(cje->flag) ||
!find_prop(cje->p, PROP_HASHCOL) ||
(cje->type == e_cmp && cje->f == NULL)) {
- l = find_one_rel(rels, cje->l);
- r = find_one_rel(rels, cje->r);
+ l = rels_a[r1[cje->tmp]];
+ r = rels_a[r2[cje->tmp]];
+ rel_mask |= h[cje->tmp];
}
-
- if (l && r && l != r) {
+ cje->tmp = 0;
+
+ if (l && r && l != r)
list_remove_data(sdje, NULL, cje);
- list_remove_data(exps, NULL, cje);
- }
}
if (l && r && l != r) {
list_remove_data(rels, NULL, l);
list_remove_data(rels, NULL, r);
- list_append(n_rels, l);
- list_append(n_rels, r);
+ if (!direct) {
+ list_append(n_rels, l);
+ list_append(n_rels, r);
+ }
/* Create a relation between l and r. Since the calling
functions rewrote the join tree, into a list of expressions
@@ -2105,43 +2176,44 @@ order_joins(visitor *v, list *rels, list
}
en = next;
}
- /* Remove other joins on the current 'n_rels' set in the
distinct list too */
- for (node *en = sdje->h; en; ) {
- node *next = en->next;
- sql_exp *e = en->data;
- if (rel_rebind_exp(v->sql, top, e))
- list_remove_data(sdje, NULL, en->data);
- en = next;
- }
fnd = 1;
}
/* build join tree using the ordered list */
- while(list_length(exps) && fnd) {
+ while(list_length(sdje) && fnd) {
fnd = 0;
/* find the first expression which could be added */
- if (list_length(sdje) > 1)
- sdje = order_join_expressions(v->sql, sdje, rels);
for(djn = sdje->h; djn && !fnd && rels->h; djn =
(!fnd)?djn->next:NULL) {
- node *ln, *rn, *en;
+ node *en;
+ l = r = NULL;
cje = djn->data;
- ln = list_find(n_rels, cje->l, (fcmp)&rel_has_exp2);
- rn = list_find(n_rels, cje->r, (fcmp)&rel_has_exp2);
-
- if (ln && rn) {
+ if ((h[cje->tmp] & rel_mask) > 0) {
+ if (rel_mask & (1L<<((r1[cje->tmp]-1)%64)))
+ l = rels_a[r1[cje->tmp]];
+ if (rel_mask & (1L<<((r2[cje->tmp]-1)%64)))
+ r = rels_a[r2[cje->tmp]];
+ }
+ if (!direct) { /* check if atleast one side in n_rels */
+ if (l && !list_find(n_rels, l, NULL))
+ l = NULL;
+ if (r && !list_find(n_rels, r, NULL))
+ r = NULL;
+ }
+
+ if (l && r) {
assert(0);
/* create a selection on the current */
- l = ln->data;
- r = rn->data;
rel_join_add_exp(v->sql->sa, top, cje);
fnd = 1;
- } else if (ln || rn) {
- if (ln) {
- l = ln->data;
- r = find_rel(rels, cje->r);
+ } else if (l || r) {
+ /* TODO: handle case for joins which need > 2
relations, ie where the current 'top' of the
+ * join tree needs to add more then one
relation */
+ rel_mask |= h[cje->tmp];
+ if (l) {
+ r = rels_a[r2[cje->tmp]];
} else {
- l = rn->data;
- r = find_rel(rels, cje->l);
+ l = r;
+ r = rels_a[r1[cje->tmp]];
}
if (!r) {
fnd = 1; /* not really, but this bails
out */
@@ -2151,10 +2223,10 @@ order_joins(visitor *v, list *rels, list
/* remove the expression from the lists */
list_remove_data(sdje, NULL, cje);
- list_remove_data(exps, NULL, cje);
list_remove_data(rels, NULL, r);
- append(n_rels, r);
+ if (!direct)
+ append(n_rels, r);
/* create a join using the current expression */
rsingle = is_single(r);
@@ -2179,8 +2251,11 @@ order_joins(visitor *v, list *rels, list
for (en = sdje->h; en; ) {
node *next = en->next;
sql_exp *e = en->data;
- if (rel_rebind_exp(v->sql, top, e))
+ if ((direct && ((e->flag <=
cmp_notequal && (h[e->tmp] & rel_mask) == h[e->tmp]) || (e->flag > cmp_notequal
&& rel_rebind_exp(v->sql, top, e)))) ||
+ (!direct && rel_rebind_exp(v->sql,
top, e))) {
+ rel_join_add_exp(v->sql->sa,
top, e);
list_remove_data(sdje, NULL,
en->data);
+ }
en = next;
}
fnd = 1;
@@ -2202,21 +2277,17 @@ order_joins(visitor *v, list *rels, list
top = nr;
}
}
+ if (list_length(sdje)) {
+ if (list_empty(exps))
+ exps = sdje;
+ else
+ exps = list_merge(exps, sdje, (fdup)NULL);
+ }
if (list_length(exps)) { /* more expressions (add selects) */
top = rel_select(v->sql->sa, top, NULL);
for(node *n=exps->h; n; n = n->next) {
sql_exp *e = n->data;
- /* find the involved relations */
-
- /* complex expressions may touch multiple base tables
- * Should be push up to extra selection. */
- /*
- l = find_one_rel(rels, e->l);
- r = find_one_rel(rels, e->r);
-
- if (l && r)
- */
if (exp_is_join_exp(e) == 0) {
sql_rel *nr = NULL;
if (is_theta_exp(e->flag)) {
_______________________________________________
checkin-list mailing list -- checkin-list@monetdb.org
To unsubscribe send an email to checkin-list-le...@monetdb.org
