Re: [HACKERS] GiST -- making my index faster makes is slower

[David Blasby]

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

---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
     joining column's datatypes do not match