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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2014-07-22 13:30:01 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2014-07-22 13:30:14 -0400 |
| commit | 6306d07122d8b6678f47c273165540de02a0d242 (patch) | |
| tree | 1598a69d5b07d7faa498b995752569dffb9e3c68 /src | |
| parent | f59c8eff7dd3dea4116a34e1890ee219f6d7f8d5 (diff) | |
| download | postgresql-6306d07122d8b6678f47c273165540de02a0d242.tar.gz postgresql-6306d07122d8b6678f47c273165540de02a0d242.zip | |
Re-enable error for "SELECT ... OFFSET -1".
The executor has thrown errors for negative OFFSET values since 8.4 (see
commit bfce56eea45b1369b7bb2150a150d1ac109f5073), but in a moment of brain
fade I taught the planner that OFFSET with a constant negative value was a
no-op (commit 1a1832eb085e5bca198735e5d0e766a3cb61b8fc). Reinstate the
former behavior by only discarding OFFSET with a value of exactly 0. In
passing, adjust a planner comment that referenced the ancient behavior.
Back-patch to 9.3 where the mistake was introduced.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 686e176e703..c19364e0018 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -2127,7 +2127,7 @@ preprocess_limit(PlannerInfo *root, double tuple_fraction, { *offset_est = DatumGetInt64(((Const *) est)->constvalue); if (*offset_est < 0) - *offset_est = 0; /* less than 0 is same as 0 */ + *offset_est = 0; /* treat as not present */ } } else @@ -2288,9 +2288,8 @@ limit_needed(Query *parse) { int64 offset = DatumGetInt64(((Const *) node)->constvalue); - /* Executor would treat less-than-zero same as zero */ - if (offset > 0) - return true; /* OFFSET with a positive value */ + if (offset != 0) + return true; /* OFFSET with a nonzero value */ } } else |