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.


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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