Index problem.
От | Dustin Sallings |
---|---|
Тема | Index problem. |
Дата | |
Msg-id | Pine.SGI.3.95.981016104749.18413A-100000@bleu.west.spy.net обсуждение исходный текст |
Список | pgsql-general |
I've got a phonebook database I'm writing, an in it is a zip code table that has ~42k zip codes indexed off the integer zip code. This work's *great* 'cept the last time I built my database and loaded the zip codes, my query didn't want to use the index I think this is 6.3.2 (is there a quick way to get the version number?). phonebook=> explain phonebook-> select person.person_key, person.first_name, person.last_name, addr_type.name as type, addrs.addr, zip.city, zip.state, zip.zip_key as zip_code from person, addr_type, addrs, zip, addr_map where addr_type.addr_type_key=addrs.addr_type_key and addrs.zip_key=zip.zip_key and addr_map.person_key=person.person_key and addr_map.addrs_key=addrs.addrs_key; NOTICE: QUERY PLAN: Nested Loop (cost=1.03 size=1 width=104) -> Nested Loop (cost=0.00 size=1 width=76) -> Nested Loop (cost=0.00 size=1 width=68) -> Nested Loop (cost=0.00 size=1 width=40) -> Seq Scan on addrs (cost=0.00 size=0 width=24) -> Seq Scan on addr_type (cost=1.10 size=3 width=16) -> Seq Scan on zip (cost=0.00 size=0 width=28) -> Seq Scan on addr_map (cost=0.00 size=0 width=8) -> Seq Scan on person (cost=1.03 size=1 width=28) ...notice the statistics are *obviously* wrong there, though I did a few vacuum verbose analyze's which seemed to do the right thing. I dropped the Index and rebuilt it, and I get this: Nested Loop (cost=2.13 size=1 width=104) -> Nested Loop (cost=1.10 size=1 width=76) -> Nested Loop (cost=0.00 size=1 width=60) -> Nested Loop (cost=0.00 size=1 width=52) -> Seq Scan on addrs (cost=0.00 size=0 width=24) -> Index Scan on zip (cost=2.05 size=42155 width=28) -> Seq Scan on addr_map (cost=0.00 size=0 width=8) -> Seq Scan on addr_type (cost=1.10 size=3 width=16) -> Seq Scan on person (cost=1.03 size=1 width=28) I also get my data back a lot faster. :) -- SA, beyond.com My girlfriend asked me which one I like better. pub 1024/3CAE01D5 1994/11/03 Dustin Sallings <dustin@spy.net> | Key fingerprint = 87 02 57 08 02 D0 DA D6 C8 0F 3E 65 51 98 D8 BE L_______________________ I hope the answer won't upset her. ____________
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