Re: [HACKERS] Neverending query on 6.5.2 over Solaris 2.5.1
От | Fernando Schapachnik |
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Тема | Re: [HACKERS] Neverending query on 6.5.2 over Solaris 2.5.1 |
Дата | |
Msg-id | 199910261247.JAA06204@ns1.via-net-works.net.ar обсуждение исходный текст |
Ответ на | Re: [HACKERS] Neverending query on 6.5.2 over Solaris 2.5.1 (Tom Lane <tgl@sss.pgh.pa.us>) |
Список | pgsql-hackers |
En un mensaje anterior, Tom Lane escribió: > Well, it's sure confused about the selectivity of WHERE activa, > all right. > > I tried to duplicate this here, by duplicating the table definition you > sent and filling it with some junk data --- about 1800 rows, 1500 of > which had activa = 't'. I found that after loading the table and > running a plain "vacuum", the system indeed estimated one row out, just > as you show above. But after "vacuum analyze", it estimated 1360 rows > out, which is a lot closer to reality (and would make a big difference > in the plan selected for a join). > > Now I know you said you did a "vacuum analyze" on the table, but > I am wondering if maybe you got confused about what you did. > Please try it again just to make sure. I tried again and now it's working better. I think the first problem was due to low shared memory available and a special factor between my keyboard and my chair ;-) Thanks for all you help! Fernando P. Schapachnik Administración de la red VIA Net Works Argentina SA Diagonal Roque Sáenz Peña 971, 4º y 5º piso. 1035 - Capital Federal, Argentina. (54-11) 4323-3333 http://www.via-net-works.net.ar
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