diff options
Diffstat (limited to 'src/backend/optimizer/plan/createplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index c77f7d40539..8abcfc576c1 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 1.152 2003/08/07 19:20:22 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.153 2003/08/08 21:41:48 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -40,9 +40,9 @@ static bool use_physical_tlist(RelOptInfo *rel); static void disuse_physical_tlist(Plan *plan, Path *path); static Join *create_join_plan(Query *root, JoinPath *best_path); static Append *create_append_plan(Query *root, AppendPath *best_path); -static Result *create_result_plan(Query *root, ResultPath * best_path); -static Material *create_material_plan(Query *root, MaterialPath * best_path); -static Plan *create_unique_plan(Query *root, UniquePath * best_path); +static Result *create_result_plan(Query *root, ResultPath *best_path); +static Material *create_material_plan(Query *root, MaterialPath *best_path); +static Plan *create_unique_plan(Query *root, UniquePath *best_path); static SeqScan *create_seqscan_plan(Path *best_path, List *tlist, List *scan_clauses); static IndexScan *create_indexscan_plan(Query *root, IndexPath *best_path, @@ -443,7 +443,7 @@ create_append_plan(Query *root, AppendPath *best_path) * Returns a Plan node. */ static Result * -create_result_plan(Query *root, ResultPath * best_path) +create_result_plan(Query *root, ResultPath *best_path) { Result *plan; List *tlist; @@ -475,7 +475,7 @@ create_result_plan(Query *root, ResultPath * best_path) * Returns a Plan node. */ static Material * -create_material_plan(Query *root, MaterialPath * best_path) +create_material_plan(Query *root, MaterialPath *best_path) { Material *plan; Plan *subplan; @@ -500,7 +500,7 @@ create_material_plan(Query *root, MaterialPath * best_path) * Returns a Plan node. */ static Plan * -create_unique_plan(Query *root, UniquePath * best_path) +create_unique_plan(Query *root, UniquePath *best_path) { Plan *plan; Plan *subplan; @@ -522,17 +522,18 @@ create_unique_plan(Query *root, UniquePath * best_path) * to unique-ify may be expressions in these variables. We have to * add any such expressions to the subplan's tlist. We then build * control information showing which subplan output columns are to be - * examined by the grouping step. (Since we do not remove any existing - * subplan outputs, not all the output columns may be used for grouping.) + * examined by the grouping step. (Since we do not remove any + * existing subplan outputs, not all the output columns may be used + * for grouping.) * - * Note: the reason we don't remove any subplan outputs is that there - * are scenarios where a Var is needed at higher levels even though it - * is not one of the nominal outputs of an IN clause. Consider - * WHERE x IN (SELECT y FROM t1,t2 WHERE y = z) - * Implied equality deduction will generate an "x = z" clause, which may - * get used instead of "x = y" in the upper join step. Therefore the - * sub-select had better deliver both y and z in its targetlist. It is - * sufficient to unique-ify on y, however. + * Note: the reason we don't remove any subplan outputs is that there are + * scenarios where a Var is needed at higher levels even though it is + * not one of the nominal outputs of an IN clause. Consider WHERE x + * IN (SELECT y FROM t1,t2 WHERE y = z) Implied equality deduction + * will generate an "x = z" clause, which may get used instead of "x = + * y" in the upper join step. Therefore the sub-select had better + * deliver both y and z in its targetlist. It is sufficient to + * unique-ify on y, however. * * To find the correct list of values to unique-ify, we look in the * information saved for IN expressions. If this code is ever used in @@ -1208,7 +1209,7 @@ fix_indxqual_sublist(List *indexqual, Relids leftvarnos; Oid opclass; - if (!IsA(clause, OpExpr) || length(clause->args) != 2) + if (!IsA(clause, OpExpr) ||length(clause->args) != 2) elog(ERROR, "indexqual clause is not binary opclause"); /* |