Re: Moving GiST index constant to parameter

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От Tom Lane
Тема Re: Moving GiST index constant to parameter
Дата
Msg-id 26034.1491145839@sss.pgh.pa.us
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Thomas Mercieca <tmercieca@msn.com> writes:
> I have tried introducing a GUC variable (entry in guc.c/config_real) and I have also tried having the parser
recognizeit (same as fillfactor is recognized), but irrelevant of what I set the value to at run-time, I always get the
sameunusual index stats (cannot reproduce results) and the following messages in the logfile, suggesting that I broke
thefunction: 

A GUC is certainly not the right thing; you should use an index storage
parameter.  However, it seems like your problem is independent of that.

> "DEBUG:  picksplit method for column 1 of index "idx2243" failed
> HINT:  The index is not optimal. To optimize it, contact a developer, or try to use the column as the second one in
theCREATE INDEX command. 
> STATEMENT:  create index idx2243 on geom_table using gist(geom)"

It looks like picksplit would necessarily fail if you tried to use
a ratio >= 0.5, or even very close to 0.5, because you'd be demanding
unachievable perfection of the split.

Beyond that observation, it's hard to say much without seeing what
you changed.
        regards, tom lane



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