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| author | Bruce Momjian <bruce@momjian.us> | 1998-03-30 19:05:10 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 1998-03-30 19:05:10 +0000 |
| commit | 01ecb2e3a03195c65d1ea55bfc9b4a47f632baec (patch) | |
| tree | 9eb12daee61bfed08b623b96e17bcc1adbe8bc88 /src/backend | |
| parent | ef0eecfa1f36cf85cef838fbcc7ed13b42c274e2 (diff) | |
| download | postgresql-01ecb2e3a03195c65d1ea55bfc9b4a47f632baec.tar.gz postgresql-01ecb2e3a03195c65d1ea55bfc9b4a47f632baec.zip | |
documentation for HAVING, clean up UNION comment.
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index 7b36d3b8e8c..e821f20a963 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.20 1998/02/26 04:33:05 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.21 1998/03/30 19:04:41 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -71,7 +71,8 @@ plan_union_queries(Query *parse) union_found = false, last_unionall_flag = false; - /* + /*------------------------------------------------------------------ + * * Do we need to split up our unions because we have UNION and UNION * ALL? * @@ -87,10 +88,25 @@ plan_union_queries(Query *parse) * * So the above query becomes: * - * Append Node { Sort and Unique { Append Node { SELECT 1 - * This is really a sub-UNION, unionClause We run a - * DISTINCT on these. { SELECT 2 SELECT 3 } } } SELECT 4 SELECT 5 } + * Append Node + * { + * Sort and Unique + * { + * Append Node + * { + * SELECT 1 This is really a sub-UNION. + * unionClause We run a DISTINCT on these. + * { + * SELECT 2 + * SELECT 3 + * } + * } + * } + * SELECT 4 + * SELECT 5 + * } * + *--------------------------------------------------------------------- */ foreach(ulist, parse->unionClause) |