Re: Mnogosearch (Was: Re: website doc search is ... )
От | Marc G. Fournier |
---|---|
Тема | Re: Mnogosearch (Was: Re: website doc search is ... ) |
Дата | |
Msg-id | 20040101144525.K913@ganymede.hub.org обсуждение исходный текст |
Ответ на | Re: Mnogosearch (Was: Re: website doc search is ... ) (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Mnogosearch (Was: Re: website doc search is ... )
(Tom Lane <tgl@sss.pgh.pa.us>)
|
Список | pgsql-general |
On Thu, 1 Jan 2004, Tom Lane wrote: > "Marc G. Fournier" <scrappy@postgresql.org> writes: > > 'k, and for todays question ... how does one 'knock up the stats target'? > > ALTER TABLE [ ONLY ] name [ * ] > ALTER [ COLUMN ] column SET STATISTICS integer > > The default is 10; try 100, or even 1000 (don't think it will let you > go higher than 1000). k, so: 186_archives=# alter table ndict8 alter column word_id set statistics 1000; ALTER TABLE followed by an 'vacuum verbose analyze ndict8', which showed an analyze of: INFO: analyzing "public.ndict8" INFO: "ndict8": 34718 pages, 300000 rows sampled, 6354814 estimated total rows vs when set at 10: INFO: analyzing "public.ndict8" INFO: "ndict8": 34718 pages, 3000 rows sampled, 6229711 estimated total rows The query @ 1000: QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------ Hash Join (cost=13918.23..76761.02 rows=81 width=8) (actual time=5199.443..5835.444 rows=13415 loops=1) Hash Cond: ("outer".url_id = "inner".rec_id) -> Index Scan using n8_word on ndict8 (cost=0.00..62761.60 rows=16075 width=8) (actual time=0.230..344.485 rows=15533loops=1) Index Cond: (word_id = 417851441) -> Hash (cost=13913.31..13913.31 rows=1968 width=4) (actual time=5198.289..5198.289 rows=0 loops=1) -> Seq Scan on url (cost=0.00..13913.31 rows=1968 width=4) (actual time=3.933..3414.657 rows=304811 loops=1) Filter: ((url || ''::text) ~~ 'http://archives.postgresql.org/%%'::text) Total runtime: 5908.778 ms (8 rows) Same query @ 10: QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------- Hash Join (cost=13918.23..26502.18 rows=17 width=8) (actual time=3657.984..4293.529 rows=13415 loops=1) Hash Cond: ("outer".url_id = "inner".rec_id) -> Index Scan using n8_word on ndict8 (cost=0.00..12567.73 rows=3210 width=8) (actual time=0.239..362.375 rows=15533loops=1) Index Cond: (word_id = 417851441) -> Hash (cost=13913.31..13913.31 rows=1968 width=4) (actual time=3657.480..3657.480 rows=0 loops=1) -> Seq Scan on url (cost=0.00..13913.31 rows=1968 width=4) (actual time=2.646..2166.632 rows=304811 loops=1) Filter: ((url || ''::text) ~~ 'http://archives.postgresql.org/%%'::text) Total runtime: 4362.375 ms (8 rows) I don't see a difference between the two, other then time changes, but that could just be that runA had a server a bit more idle then runB ... something I'm not seeing here? ---- Marc G. Fournier Hub.Org Networking Services (http://www.hub.org) Email: scrappy@hub.org Yahoo!: yscrappy ICQ: 7615664
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