diff options
Diffstat (limited to 'src/backend/optimizer/plan/createplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 9cd8a11159a..4109ab25364 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.89 2000/04/12 17:15:21 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.90 2000/05/23 16:56:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -27,6 +27,7 @@ #include "optimizer/planmain.h" #include "optimizer/restrictinfo.h" #include "optimizer/tlist.h" +#include "parser/parse_expr.h" #include "utils/lsyscache.h" #include "utils/syscache.h" @@ -722,7 +723,7 @@ create_hashjoin_node(HashPath *best_path, * machinery needs. * * We have three tasks here: - * * Var nodes representing index keys must have varattno equal to the + * * Index keys must be represented by Var nodes with varattno set to the * index's attribute number, not the attribute number in the original rel. * * indxpath.c may have selected an index that is binary-compatible with * the actual expression operator, but not exactly the same datatype. @@ -789,7 +790,7 @@ fix_indxqual_references(List *indexquals, IndexPath *index_path) * Fix the sublist of indexquals to be used in a particular scan. * * For each qual clause, commute if needed to put the indexkey operand on the - * left, and then change its varno. (We do not need to change the other side + * left, and then fix its varattno. (We do not need to change the other side * of the clause.) Also change the operator if necessary. */ static List * @@ -863,8 +864,16 @@ static Node * fix_indxqual_operand(Node *node, int baserelid, Form_pg_index index, Oid *opclass) { + /* + * We represent index keys by Var nodes having the varno of the base + * table but varattno equal to the index's attribute number (index + * column position). This is a bit hokey ... would be cleaner to use + * a special-purpose node type that could not be mistaken for a regular + * Var. But it will do for now. + */ if (IsA(node, Var)) { + /* If it's a var, find which index key position it occupies */ if (((Var *) node)->varno == baserelid) { int varatt = ((Var *) node)->varattno; @@ -877,6 +886,7 @@ fix_indxqual_operand(Node *node, int baserelid, Form_pg_index index, Node *newnode = copyObject(node); ((Var *) newnode)->varattno = pos + 1; + /* return the correct opclass, too */ *opclass = index->indclass[pos]; return newnode; } @@ -890,22 +900,17 @@ fix_indxqual_operand(Node *node, int baserelid, Form_pg_index index, } /* - * Else, it must be a func expression representing a functional index. - * - * Currently, there is no need for us to do anything here for functional - * indexes. If nodeIndexscan.c sees a func clause as the left or - * right-hand toplevel operand of an indexqual, it assumes that that - * is a reference to the functional index's value and makes the - * appropriate substitution. (It would be cleaner to make the - * substitution here, I think --- suspect this issue if a join clause - * involving a function call misbehaves...) + * Else, it must be a func expression matching a functional index. + * Since we currently only support single-column functional indexes, + * the returned varattno must be 1. */ + Assert(is_funcclause(node)); /* not a very thorough check, but easy */ + /* indclass[0] is the only class of a functional index */ *opclass = index->indclass[0]; - /* return the unmodified node */ - return node; + return (Node *) makeVar(baserelid, 1, exprType(node), -1, 0); } /* |