Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> writes:
> Looking at the big picture, however, the real problem with all those
> makesign() calls is that they happen in the first place. They happen
> when gist needs to choose which child page to place a new tuple on. It
> calls the penalty for every item on the internal page, always passing
> the new key as the 2nd argument, along the lines of:
> for (all items on internal page)
> penalty(item[i], newitem);
> At every call, gtrgm_penalty() has to calculate the signature for
> newitem, using makesign(). That's an enormous waste of effort, but
> there's currently no way gtrgm_penalty() to avoid that.
Hmm. Are there any other datatypes for which the penalty function has
to duplicate effort? I'm disinclined to fool with this if pg_trgm is
the only example ... but if it's not, maybe we should do something
about that instead of micro-optimizing makesign.
regards, tom lane
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