Re: Moving GiST index constant to parameter

Thomas Mercieca <tmercieca(at)msn(dot)com> writes:
> I have tried introducing a GUC variable (entry in guc.c/config_real) and I have also tried having the parser recognize it (same as fillfactor is recognized), but irrelevant of what I set the value to at run-time, I always get the same unusual index stats (cannot reproduce results) and the following messages in the logfile, suggesting that I broke the function:

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 the CREATE 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