bug in hash indexes???
От | Jakub Ouhrabka |
---|---|
Тема | bug in hash indexes??? |
Дата | |
Msg-id | Pine.LNX.4.33.0107201345260.8557-100000@u-pl0 обсуждение исходный текст |
Ответ на | Re: replication? (Adam Manock <abmanock@planetcable.net>) |
Ответы |
Re: bug in hash indexes???
(Tom Lane <tgl@sss.pgh.pa.us>)
plpgsql function and constraints (Jakub Ouhrabka <jouh8664@ss1000.ms.mff.cuni.cz>) |
Список | pgsql-general |
hi, i observed strange behavior using hash index. is it a known bug? the index was created before loading data into table. when i recreate the tc01_tc01pk____idx index everything is ok. and i can see some other strange things with hash indexes in other tables. is it possible that i'm using hash indexes in a bad way? or is it because of using multiple indexes on one column? any ideas? thanks, kuba db_c01=# select version(); version --------------------------------------------------------------- PostgreSQL 7.1.2 on i686-pc-linux-gnu, compiled by GCC 2.95.4 -- running debian, kernel 2.4, installed from .deb package db_c01=# \d tc01 Table "tc01" Attribute | Type | Modifier -----------+-----------------------+-------------------------------------------------------- tc01pk___ | integer | not null default nextval('"tc01_tc01pk____seq"'::text) tc01mobil | character varying(30) | not null tc01jmeno | character varying(50) | tc01prijm | character varying(50) | tc01zusta | double precision | not null tc03pk___ | integer | not null tc01akt__ | boolean | not null default 't'::bool Indices: tc01_pkey, tc01_tc01pk____idx, tc01_tc01prijm_idx -- tc01_tc01pk is a hash index on tc01pk___ -- tc01_pkey is a btree index on tc01pk___ db_c01=# explain select oid, * from tc01 order by tc01pk___ desc LIMIT 1; Limit (cost=0.00..0.06 rows=1 width=57) -> Index Scan Backward using tc01_pkey on tc01 (cost=0.00..59.00 rows=1000 width=57) db_c01=# select oid, * from tc01 order by tc01pk___ desc LIMIT 1; oid | tc01pk___ | tc01mobil | tc01jmeno | tc01prijm | tc01zusta | tc03pk__ ---------+-----------+------------+-----------+-----------+-----------+--------- 1469963 | 10003 | 0609123456 | pepa | vomacka | 10000 | (1 row) db_c01=# explain select oid, * from tc01 where tc01pk___ = 10003; Index Scan using tc01_tc01pk____idx on tc01 (cost=0.00..8.14 rows=10 width=57) db_c01=# select oid, * from tc01 where tc01pk___ = 10003; oid | tc01pk___ | tc01mobil | tc01jmeno | tc01prijm | tc01zusta | tc03pk___ | t -----+-----------+-----------+-----------+-----------+-----------+-----------+-- (0 rows)
В списке pgsql-general по дате отправления: