* returns true, otherwise returns false.
*
* Optionally returns pointers to the extracted Var/Const nodes, when passed
- * non-null pointers (varp, cstp and isgtp). The isgt flag specifies whether
- * the Var node is on the left (false) or right (true) side of the operator.
+ * non-null pointers (varp, cstp and varonleftp). The varonleftp flag specifies
+ * on which side of the operator we found the Var node.
*/
bool
-examine_opclause_expression(OpExpr *expr, Var **varp, Const **cstp, bool *isgtp)
+examine_opclause_expression(OpExpr *expr, Var **varp, Const **cstp, bool *varonleftp)
{
Var *var;
Const *cst;
- bool isgt;
+ bool varonleft;
Node *leftop,
*rightop;
{
var = (Var *) leftop;
cst = (Const *) rightop;
- isgt = false;
+ varonleft = true;
}
else if (IsA(leftop, Const) && IsA(rightop, Var))
{
var = (Var *) rightop;
cst = (Const *) leftop;
- isgt = true;
+ varonleft = false;
}
else
return false;
if (cstp)
*cstp = cst;
- if (isgtp)
- *isgtp = isgt;
+ if (varonleftp)
+ *varonleftp = varonleft;
return true;
}
OpExpr *expr = (OpExpr *) clause;
FmgrInfo opproc;
- /* get procedure computing operator selectivity */
- RegProcedure oprrest = get_oprrest(expr->opno);
-
/* valid only after examine_opclause_expression returns true */
Var *var;
Const *cst;
- bool isgt;
+ bool varonleft;
fmgr_info(get_opcode(expr->opno), &opproc);
/* extract the var and const from the expression */
- if (examine_opclause_expression(expr, &var, &cst, &isgt))
+ if (examine_opclause_expression(expr, &var, &cst, &varonleft))
{
int idx;
if (RESULT_IS_FINAL(matches[i], is_or))
continue;
- switch (oprrest)
- {
- case F_EQSEL:
- case F_NEQSEL:
-
- /*
- * We don't care about isgt in equality, because
- * it does not matter whether it's (var op const)
- * or (const op var).
- */
- match = DatumGetBool(FunctionCall2Coll(&opproc,
- DEFAULT_COLLATION_OID,
- cst->constvalue,
- item->values[idx]));
-
- break;
-
- case F_SCALARLTSEL: /* column < constant */
- case F_SCALARLESEL: /* column <= constant */
- case F_SCALARGTSEL: /* column > constant */
- case F_SCALARGESEL: /* column >= constant */
-
- /*
- * First check whether the constant is below the
- * lower boundary (in that case we can skip the
- * bucket, because there's no overlap).
- */
- if (isgt)
- match = DatumGetBool(FunctionCall2Coll(&opproc,
- DEFAULT_COLLATION_OID,
- cst->constvalue,
- item->values[idx]));
- else
- match = DatumGetBool(FunctionCall2Coll(&opproc,
- DEFAULT_COLLATION_OID,
- item->values[idx],
- cst->constvalue));
-
- break;
- }
+ /*
+ * First check whether the constant is below the lower
+ * boundary (in that case we can skip the bucket, because
+ * there's no overlap).
+ */
+ if (varonleft)
+ match = DatumGetBool(FunctionCall2Coll(&opproc,
+ DEFAULT_COLLATION_OID,
+ item->values[idx],
+ cst->constvalue));
+ else
+ match = DatumGetBool(FunctionCall2Coll(&opproc,
+ DEFAULT_COLLATION_OID,
+ cst->constvalue,
+ item->values[idx]));
/* update the match bitmap with the result */
matches[i] = RESULT_MERGE(matches[i], is_or, match);