Re: Re: GiST optimizing memmoves in gistplacetopage for fixed-size updates [PoC]

Andrew Borodin wrote:
> Thank you, Amit.
> 
> Currently, if WAL reconstruct page in another order it won't be a problem.

We require that replay of WAL leads to identical bytes than the
original.  Among other things, this enables use of a tool that verifies
that WAL is working correctly simply by comparing page images.  So
please fix it instead of just verifying that this works for GiST.

By the way, BRIN indexes have a need of this operation too.  The current
approach is to call PageIndexDeleteNoCompact followed by PageAddItem.
I suppose it would be beneficial to use your new routine there too.

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Álvaro Herrera                http://www.2ndQuadrant.com/
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