Andrew Dunstan wrote:
Heikki Linnakangas wrote:
Andrew Dunstan wrote:
I'm still a bit worried about applying it unless it gets some
adaptive behaviour or something so that we don't cause any serious
performance regressions in some cases.
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I'll try to come up with something. At the most conservative end, we
could fall back to the current method on the first escape, quote or
backslash character.
That's far too conservative, I think. Somewhere a bit short of your
observed breakeven point seems about right.
The problem is, you don't know how many "stop" characters there is until
you've counted them.
We could fall back after X such characters, or only start using memchr
after seeing 8 consecutive non-stop characters. Whatever we choose, the
heuristic needs to be very simple and fast to check, otherwise we just
introduce more overhead trying to decide which method to use.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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