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

Tom Lane wrote:

> I'd suggest profiling the backend with both key types to get an idea of
> where the time is going.

I've been trying to use gprof to do some profiling, but I'm having 
troubles.  Whats the best way to profile?


> PS: actually, allowing for the 12-byte index tuple overhead, you
> couldn't have even twice as many keys per page.  So there's something
> mighty odd here.  Keep us posted.

Using the old system, I'd get about 7 internal node hits and about 110 
"leaf" hits.  Under the new one, I get about 4 internal node hits and 
about 160 "leaf" hits.

I'm just in the process of changing the key to:

typedef struct
{float xmin;float ymin;float xmax;float ymax;char  junk[16]; // make the 16 byte type into 32!
} BOX2DFLOAT4;

To see what happens.

dave