Andrew Dunstan wrote:
Heikki Linnakangas wrote:
Here's a patch to speed up CopyReadAttributesCSV. On the test case
I've been playing with, loading the TPC-H partsupp table, about 20%
CopyReadAttributesCSV (inlined into DoCopy, DoCopy itself is
insignificant):
[snip]
The trick is to split the loop in CopyReadAttributesCSV into two
parts, inside quotes, and outside quotes, saving some instructions in
both parts.
Your mileage may vary, but I'm quite happy with this. I haven't tested
it much yet, but I wouldn't expect it to be a loss in any interesting
scenario. The code also doesn't look much worse after the patch,
perhaps even better.
This looks sane enough, and worked for me in testing, so I'm going to
apply it shortly. I'll probably add a comment or two about how the loops
interact.
Thanks.
FWIW, I did some more performance testing, with input consisting of a
lot of quotes, and it seems the performance gain holds even then. I was
not able to find an input where the new version performs worse.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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