Re: Any "guide to indexes" exists?

bilekj@gmail.com ("Jan Bilek") writes:
> I was asking for these "specific/particular reasons". Im not the
> database developer, to be expert on indexes (i know whats btree and
> hash - gin and gist are rather mysterious for me).
> Ok - btree is fine, but sometimes could be better to use gist - my
> question is: when is that "sometimes"? Unless i know how to use the
> indexes, then they are useless for me - am i right?
>
> Note: We are using gin with tsearch2 vectors, but here we had no
> choice -
> tsearch2 works only with gin and gist.

>> You use btree unless you have a specific, particular reason to use
>> one of the
>> other ones.

Peter's comments are pretty germane.

You use btree if you can.  btree is fine for anything where values are
reasonable "scalar," and compare to one another either in a
straightforward scalar fashion, or piece-wise scalar, as with compound
keys where you start by comparing the first component, then, if it's
equal, considering the second, and so on.

You use GIST if you *need to*, if you have a data structure where
values *aren't* scalar, *can't* be compared (e.g. - where you can't
simply say A > B, B > C).
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