[HACKERS] Parameters of GiST indexes

[Alexander Korotkov]

Hi hackers,

I found that some parameters of GiST implementation are builin in the code.
For example, following can be found in the backend/utils/adt/tsgistidx.c:

#define SIGLENINT  31            /* >121 => key will toast, so it will not
work
                                 * !!! */

#define SIGLEN    ( sizeof(int4) * SIGLENINT )
#define SIGLENBIT (SIGLEN * BITS_PER_BYTE)

I think that such parameters don't have optimal value for all the cases; and
it would be a great option to let user define such parameters for particular
index.
For example, following syntax can be used:

CREATE INDEX name ON table USING gist(column) WITH (SIGLENINT=63);

With best regards,
Korotkov Alexander.