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List:       postgresql-general
Subject:    Re: [HACKERS] Question about indexes
From:       Tom Lane <tgl () sss ! pgh ! pa ! us>
Date:       2004-01-31 0:50:23
Message-ID: 23292.1075510223 () sss ! pgh ! pa ! us
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Greg Stark <gsstark@mit.edu> writes:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
>> ORing and ANDing of such bitmaps still works, with the understanding
>> that it's lossy and you have to double check each retrieved tuple.

> That would make it really hard to ever clear the bits.

We're speaking of in-memory bitmaps constructed on-the-fly here.  You're
right that it wouldn't work for persistent indexes, but I'm not very
interested in that case at the moment ...

			regards, tom lane

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