For some time I have been working on removing some inefficiencies from a
large DW-type app. This app does a large daily batch update, and this is
what is the major bottleneck. One of the things I have been doing is to
remove unnecessary updates (which are particualrly expensive in our
index-rich setting). Several times now I have wished that there was a
switch on the UPDATE command that said "do minimal instead of maximal
updating". i.e., don't update records with identical replacements. At
the moment I have to write things like:
update tname set foo = bar ... where foo is null or foo <> bar ...
This becomes more than tedious when the update might be setting thirty
or forty fields, and I have to write such tests for each of them. It
would be so much nicer to be able to write something like:
update tname minimally set foo = bar ...
Is this an insane idea, or would it be possible, practical and useful?
cheers
andrew
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TIP 9: In versions below 8.0, the planner will ignore your desire to
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