BUG REPORT - Mailing list pgsql-bugs
From | Marcin Polak |
---|---|
Subject | BUG REPORT |
Date | |
Msg-id | Pine.LNX.3.96.990319194851.1247A-200000@lokalik.on.the.Sun Whole thread Raw |
List | pgsql-bugs |
============================================================================ POSTGRESQL BUG REPORT TEMPLATE ============================================================================ Your name :Marcin Polak Your email address :marcin@indigo.pl System Configuration --------------------- Architecture (example: Intel Pentium) :Intel Pentium Operating System (example: Linux 2.0.26 ELF) :Linux 2.0.35 ELF PostgreSQL version (example: PostgreSQL-6.4) :PostgreSQL-6.4.2 Compiler used (example: gcc 2.8.0) :egcs-1.1b-2 Please enter a FULL description of your problem: ------------------------------------------------ After creating index on a text field (1000000 records), Postgres doesn't give proper answer on a query using this index. Please describe a way to repeat the problem. Please try to provide a concise reproducible example, if at all possible: ---------------------------------------------------------------------- I've created database with a python sript (attached) It makes: "create table tt2_1 (ntt int, nttext int, ntttext varchar(50) )" and then insert 1000000 records. Then I've created index: create index i1 on tt2_1(ntttext); -- index on third column When I'm connected with psql, I'm doing: select * from tt2_1 where nttext = 123456 and ntttext = '123456123456123456'; and answer is: ntt|nttext| ntttext ------+------+------------------ 123456|123456|123456123456123456 (1 row) and that's right; But on: marcin=> select * from tt2_1 where ntttext = '123456123456123456'; ntt|nttext|ntttext ---+------+------- (0 rows) and that's not right, am I right :-) ? It happens when I'm using similar like condition, like "blah blah ntttext like '123456%' " What more: postgres is run with parameters: -B 1000 -o -F If you know how this problem might be fixed, list the solution below: --------------------------------------------------------------------- Sorry :-(. BTW. How big database you think, Postgres can manage with? PS. My interesting observation is, that if I create six or seven tables (I don't remember exactly how many) with 1000 to 5000 records and do simple "SELECT" using all tables Postgres answers in a second (with indices), and with one more table, when GEQO turns on, I'm getting answer in 30 seconds. I can't see, in which condition it helps? Regards from Poland Marcin #!/usr/bin/python import pg c=pg.connect("marcin") for i in range(1,2): qs = "drop table tt2_%d"%i print qs c.query(qs ) qs = "create table tt2_%d (ntt int, nttext int, ntttext varchar(50) )"%i print qs c.query(qs ) for j in range(1,1000000): qs = "insert into tt2_%d values(%d, %d, '%d%d%d')"%(i,j,j,j,j,j) print qs c.query(qs )
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