performance advice needed: join vs explicit subselect
От | Karsten Hilbert |
---|---|
Тема | performance advice needed: join vs explicit subselect |
Дата | |
Msg-id | 20090127181205.GA3820@merkur.hilbert.loc обсуждение исходный текст |
Ответы |
Re: performance advice needed: join vs explicit subselect
Re: performance advice needed: join vs explicit subselect Re: performance advice needed: join vs explicit subselect |
Список | pgsql-general |
Hello all, maybe some general advice can be had on this: table test_results modified_by integer foreign key staff(pk), intended_reviewer integer foreign key staff(pk), actual_reviewer integer foreign key staff(pk) (this table will contain millions of rows) table staff pk integer name text (this table will contain at most 50 rows) Now I want to set up a view which aggregates test results with staff names for all three foreign keys. This would mean I would either have to - join test_results to staff three times, once for each of the foreign keys, this is going to be messy with tracking table aliases, duplicate column names etc - write three explicit sub-selects for the columns I want to denormalize into the view definition Is there general advice as to which of the alternatives is worse under most if not all circumstances ? Thanks, Karsten -- GPG key ID E4071346 @ wwwkeys.pgp.net E167 67FD A291 2BEA 73BD 4537 78B9 A9F9 E407 1346
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