Re: GiST -- making my index faster makes is slower

Humm -- strange results here:

typedef struct
{
float xmin;
float ymin;
float xmax;
float ymax;
} BOX2DFLOAT4;

This takes about 18,000 ms to do a nested query with 10,000 iterations.

typedef struct
{
float xmin;
float ymin;
float xmax;
float ymax;
char junk[16];
} BOX2DFLOAT4;

This takes about 15,000 ms to do a nested query with 10,000 iterations.

typedef struct
{
double xmin;
double ymin;
double xmax;
double ymax;
} BOX2DFLOAT4;

This takes about 1500 ms to do a nested query with 10,000 iterations.
Yes - that almost 14 seconds faster!

This doesnt make a lot of sense since the only part of the GiST index
thats being called that actually looks at the bounding boxes is this:

retval = (((key->xmax>= query->xmax) &&
(key->xmin <= query->xmax)) ||
((query->xmax>= key->xmax) &&
(query->xmin<= key->xmax)))
&&
(((key->ymax>= query->ymax) &&
(key->ymin<= query->ymax)) ||
((query->ymax>= key->ymax) &&
(query->ymin<= key->ymax)));

dave