Re: Insert performance and multi-column index order - Mailing list pgsql-performance

From Tom Lane
Subject Re: Insert performance and multi-column index order
Date
Msg-id 11764.1246058345@sss.pgh.pa.us
Whole thread Raw
In response to Insert performance and multi-column index order  (bob_lunney@yahoo.com)
List pgsql-performance
bob_lunney@yahoo.com writes:
> Why would changing the column order on a unique index cause data loading or index servicing to slow down?  Page
splitsin the b-tree, maybe? 

Yeah, perhaps.  Tell us about the data distributions in the columns?
Is there any ordering to the keys that're being inserted?

It's not in the least surprising that different column orders might be
better or worse suited for particular queries.  I'm mildly interested
in the question of why the bulk load speed is different, though.

            regards, tom lane

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