Update of /cvsroot/monetdb/pathfinder/compiler/algebra/opt
In directory 23jxhf1.ch3.sourceforge.com:/tmp/cvs-serv5053/algebra/opt
Modified Files:
opt_complex.c
Log Message:
-- Add rewrites for thetajoins:
* remove thetajoin with a one-row literal table and
* replace thetajoin by eqjoin if the join behaves like a mapping join.
U opt_complex.c
Index: opt_complex.c
===================================================================
RCS file: /cvsroot/monetdb/pathfinder/compiler/algebra/opt/opt_complex.c,v
retrieving revision 1.70
retrieving revision 1.71
diff -u -d -r1.70 -r1.71
--- opt_complex.c 6 Feb 2009 13:01:07 -0000 1.70
+++ opt_complex.c 9 Mar 2009 14:48:13 -0000 1.71
@@ -72,6 +72,69 @@
}
/**
+ * Replace a thetajoin with a one-row literal table by a selection.
+ */
+static PFla_op_t *
+replace_thetajoin (PFla_op_t *p, bool replace_left)
+{
+ PFla_op_t *lp = replace_left ? L(p) : R(p),
+ *res = replace_left ? R(p) : L(p);
+
+ assert (p->kind == la_thetajoin &&
+ PFprop_card (lp->prop) &&
+ (lp->kind == la_lit_tbl ||
+ (lp->kind == la_project && L(lp)->kind == la_lit_tbl)));
+
+ /* attach all columns of the to-be-replaced side
+ to the other side */
+ for (unsigned int i = 0; i < lp->schema.count; i++) {
+ assert (PFprop_const (p->prop,
+ lp->schema.items[i].name));
+ res = attach (res,
+ lp->schema.items[i].name,
+ PFprop_const_val (
+ p->prop,
+ lp->schema.items[i].name));
+ }
+
+ /* evaluate selections on the relation */
+ for (unsigned int i = 0; i < p->sem.thetajoin.count; i++) {
+ PFalg_col_t col1 = p->sem.thetajoin.pred[i].left,
+ col2 = p->sem.thetajoin.pred[i].right,
+ new = PFcol_new (col1),
+ tmp;
+ switch (p->sem.thetajoin.pred[0].comp) {
+ case alg_comp_eq:
+ res = eq (res, new, col1, col2);
+ break;
+ case alg_comp_gt:
+ res = gt (res, new, col1, col2);
+ break;
+ case alg_comp_ge:
+ tmp = PFcol_new (col1);
+ res = not (gt (res, tmp, col2, col1), new, tmp);
+ break;
+ case alg_comp_lt:
+ res = gt (res, new, col2, col1);
+ break;
+ case alg_comp_le:
+ tmp = PFcol_new (col1);
+ res = not (gt (res, tmp, col1, col2), new, tmp);
+ break;
+ case alg_comp_ne:
+ tmp = PFcol_new (col1);
+ res = not (eq (res, tmp, col1, col2), new, tmp);
+ break;
+ }
+ res = select_ (res, new);
+ }
+ /* remove additional columns */
+ return PFla_project_ (res,
+ p->schema.count,
+ PFalg_proj_create (p->schema));
+}
+
+/**
* This function checks for the following bigger pattern:
*
* |
@@ -1300,6 +1363,45 @@
}
break;
+ case la_thetajoin:
+ /* rewrite thetajoin into equi-join if it seems to be a mapping
join */
+ if (p->sem.thetajoin.count == 1 &&
+ p->sem.thetajoin.pred[0].comp == alg_comp_eq &&
+ ((PFprop_key_left (p->prop, p->sem.thetajoin.pred[0].left) &&
+ PFprop_subdom (p->prop,
+ PFprop_dom_right (p->prop,
+
p->sem.thetajoin.pred[0].right),
+ PFprop_dom_left (p->prop,
+
p->sem.thetajoin.pred[0].left))) ||
+ (PFprop_key_right (p->prop, p->sem.thetajoin.pred[0].right) &&
+ PFprop_subdom (p->prop,
+ PFprop_dom_left (p->prop,
+
p->sem.thetajoin.pred[0].left),
+ PFprop_dom_right (p->prop,
+
p->sem.thetajoin.pred[0].right))))) {
+ *p = *PFla_eqjoin (L(p), R(p),
+ p->sem.thetajoin.pred[0].left,
+ p->sem.thetajoin.pred[0].right);
+ modified = true;
+ }
+ /* unfold a thetajoin with a one-row literal table */
+ else if (PFprop_card (L(p)->prop) == 1 &&
+ (L(p)->kind == la_lit_tbl ||
+ (L(p)->kind == la_project &&
+ LL(p)->kind == la_lit_tbl))) {
+ *p = *replace_thetajoin (p, true);
+ modified = true;
+ }
+ /* unfold a thetajoin with a one-row literal table */
+ else if (PFprop_card (R(p)->prop) == 1 &&
+ (R(p)->kind == la_lit_tbl ||
+ (R(p)->kind == la_project &&
+ RL(p)->kind == la_lit_tbl))) {
+ *p = *replace_thetajoin (p, false);
+ modified = true;
+ }
+ break;
+
case la_cross:
/* PFprop_icols_count () == 0 is also true
for nodes without inferred properties
@@ -2445,11 +2547,13 @@
split_rowid_for_side_effects (root);
while (modified) {
- /* Infer key, icols, domain, reqval,
+ /* Infer key, const, icols, domain, reqval,
and refctr properties first */
PFprop_infer_lineage (root);
PFprop_infer_functional_dependencies (root);
+ /* card property inferred by key */
PFprop_infer_key (root);
+ PFprop_infer_const (root);
PFprop_infer_level (root);
PFprop_infer_composite_key (root);
PFprop_infer_icol (root);
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