| From: | isayko(dot)alexey(at)gmail(dot)com |
|---|---|
| To: | pgsql-bugs(at)postgresql(dot)org |
| Subject: | BUG #14563: count(*) gives a wrong result in PostgreSQL for some regex with pg_trm/GIN index |
| Date: | 2017-02-22 11:14:46 |
| Message-ID: | 20170222111446.1256.67547@wrigleys.postgresql.org |
| Views: | Whole Thread |Raw Message |Download mbox |Resend email |
| Thread: | |
| Lists: | pgsql-bugs |
The following bug has been logged on the website:
Bug reference: 14563
Logged by: Alexey Isayko
Email address: isayko(dot)alexey(at)gmail(dot)com
PostgreSQL version: 9.6.1
Operating system: Windows 10.0.14393 x64
Description:
When using some RE to filter rows on gin-indexed column with pg_trm,
count(*) could give a wrong result (zero instead of real count):
CREATE EXTENSION pg_trgm;
CREATE TABLE t (
s text
);
CREATE INDEX ON t USING gin (s gin_trgm_ops);
INSERT INTO t VALUES ('12-34');
SET enable_seqscan = OFF; -- to force using the index on our small table
SELECT count(*) FROM t WHERE s~'\d{2}[-]?\d{2}'; -- gives me 0 and it's
wrong
But if we will turn on seq scans, we will get the correct result:
SET enable_seqscan = ON;
SELECT count(*) FROM t WHERE s~'\d{2}[-]?\d{2}'; -- gives me 1 and it's
correct
Same behaviour I get with 9.5.4 (windows and linux) and 9.6.1 (windows)
versions of the PostgreSQL
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Terje Elde | 2017-02-22 14:53:06 | Re: BUG #14559: Error message of too many clients. |
| Previous Message | prakash ramakrishnan | 2017-02-22 11:10:28 | Error mtk 11009 |