Re: LIKE, leading percent, bind parameters and indexes
От | Martijn van Oosterhout |
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Тема | Re: LIKE, leading percent, bind parameters and indexes |
Дата | |
Msg-id | 20060529065212.GA14432@svana.org обсуждение исходный текст |
Ответ на | Re: LIKE, leading percent, bind parameters and indexes (Tom Lane <tgl@sss.pgh.pa.us>) |
Список | pgsql-hackers |
On Sat, May 27, 2006 at 11:52:40AM -0400, Tom Lane wrote: > Martijn van Oosterhout <kleptog@svana.org> writes: > > How about the suggestion of using a sequential index scan like the > > recent changes to VACUUM in the case that there are no regular index > > quals? > > Nonstarter (hint: the solution we found for VACUUM assumes there can > be only one). Bummer, I was envisioning allowing index AMs to have another access method, the unordered sequential scan. Just like we consider a random access of a real table to be more expensive than a seq scan, and index scan that seeks a lot would be more expensive that a sequential scan. So if you know you're going to scan most of an index, scanning sequentially would be cheaper... Ah well, Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.
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