Why Select Count(*) from table - took over 20 minutes?
От | Ozz Nixon |
---|---|
Тема | Why Select Count(*) from table - took over 20 minutes? |
Дата | |
Msg-id | D4718551-6E2A-4840-8BCF-20901EA0E570@gmail.com обсуждение исходный текст |
Ответ на | Re: what can depend on index (Szymon Guz <mabewlun@gmail.com>) |
Ответы |
Re: Why Select Count(*) from table - took over 20
minutes?
Re: Why Select Count(*) from table - took over 20 minutes? Re: Why Select Count(*) from table - took over 20 minutes? Re: Why Select Count(*) from table - took over 20 minutes? Re: Why Select Count(*) from table - took over 20 minutes? |
Список | pgsql-general |
I am the only user on this system right now, and one table select count(*) took over 20 minutes: wikitags exists and has 58,988,656 records. Structure (in pascal) is: quer.SQL.Add('create table '+DBTags+' ('); quer.SQL.Add(' pagename '+SQL_TITLE+'(100) not null,'); quer.SQL.Add(' tagword '+SQL_TITLE+'(15) not null,'); quer.SQL.Add(' soundex2 '+SQL_TITLE+'(4) not null,'); quer.SQL.Add(' metaphone '+SQL_TITLE+'(15) not null,'); quer.SQL.Add(' metaphone2 '+SQL_TITLE+'(22) not null,'); quer.SQL.Add(' carverphone '+SQL_TITLE+'(22) not null,'); quer.SQL.Add(' instances '+SQL_INT32+' not null,'); if SQL_NAME_PRIMARY_KEYS then quer.SQL.Add(' constraint '+DBTags+'_PK'); quer.SQL.Add(' primary key(pagename, tagword, instances)'); quer.SQL.Add(')'); where SQL_TITLE = 'varchar', SQL_IN32 = 'int' I have hung off indexes for each column, to resolve my previous "performance" issue from 3+ weeks ago. However, COUNT() isstill dog slow - this table is a write once, read many... *never* update, nor delete. Any suggestions?
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