git.postgresql.org Git - postgresql.git/commitdiff

git projects / postgresql.git / commitdiff

Re-enable error for "SELECT ... OFFSET -1".

2014年7月22日 17:30:01 +0000 (13:30 -0400)

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.

src/backend/optimizer/plan/planner.c patch | blob | blame | history

diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c

index f2c9c99b7f69edac124615acc8dc92d0f872e5a8..e1480cda2470cc09cdd9358e03ac403df01babc5 100644 (file)

--- a/src/backend/optimizer/plan/planner.c

+++ b/src/backend/optimizer/plan/planner.c

@@ -2335,7 +2335,7 @@ 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 */

}