On Wed, 28 Apr 2004 09:05:04 -0400, Tom Lane <[EMAIL PROTECTED]> wrote:[ ... visibility information in index tuples ... ]
Storing that information would at least double the overhead space used for each index tuple. The resulting index bloat would significantly slow index operations by requiring more I/O. So it's far from clear that this would be a win, even for those who care only about select speed.
While the storage overhead could be reduced to 1 bit (not a joke)
You mean adding an isLossy bit and only where it is set the head tuple has to be checked for visibility, if it is not set the head tuple does not have to be checked?
we'd still have the I/O overhead of locating and updating index tuples for every heap tuple deleted/updated.
Would there be additional I/O for the additional bit in the index tuple (I am unable to find the layout of index tuple headers in the docs)?
Jochem
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