Re: Re: Does PostgreSQL support EXISTS?
От | Bruce Momjian |
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Тема | Re: Re: Does PostgreSQL support EXISTS? |
Дата | |
Msg-id | 200106131553.f5DFrZs11003@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: Re: Does PostgreSQL support EXISTS? (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Re: Does PostgreSQL support EXISTS?
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Список | pgsql-general |
> Bruce Momjian <pgman@candle.pha.pa.us> writes: > > Are we anywhere with optimizing IN to EXISTS? I didn't think there was > > any work being done in that area. > > I don't think it's that hard to do within the outer-join mechanism, > except for this little issue about NULLs. The planner already makes > querytree alterations of comparable complexity, to deal with views and > subselects... Doing that would elimate the need for query sources, at least for a while. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
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