GiST for 7.1 !! - Mailing list pgsql-hackers

Hi,

we've almost totally rewrite gist.c because old code and algorithm
were not suitable for variable size keys. I think it might be
submitted into 7.1 beta source tree. We have fixed several bugs and
memory leaks. Version for 7.0.3 is also available.
Sampe application for contrib area - implementation RD-Tree and index support
for int arrays I'll submit later (Need some documentation).
Regards,
    Oleg


Here is a README.gist
--------------------------------
New version of gist.c for PostgreSQL 7.1

New feature:  1. Support of variable size keys - new algorithm of insertion to tree     (GLI - gist layrered
insertion).Previous algorithm was implemented     as described in paper by Joseph M. Hellerstein et.al     "Generalized
SearchTrees for Database Systems".  This (old)     algorithm was not suitable for variable size keys and could be
noteffective ( walking up-down ) in case of multiple levels split
 
Bug fixed:  1. fixed bug in gistPageAddItem - key values were written to disk     uncompressed. This caused failure if
decompressionfunction     does real job.  2. NULLs handling - we keep NULLs in tree. Right way is to remove them,
butwe don't know how to inform vacuum about index statistics. This is     just cosmetic warning message (like in case
withR-Tree),     but I'm not sure how to recognize real problem if we remove NULLs     and suppress this warning as Tom
suggested. 3. various memory leaks
 

All our tests and Gene Selcov's regression tests passed ok.
We have version also for 7.0.3
Sample application which utilize RD-Tree for index support of
int arrays is in contrib/intarray (will be submitted separately).

TODO:

1. Description of GLI algorithm
2. regression test for GiST (based on RD-Tree)

This work was done by Teodor Sigaev (teodor@stack.net) and
Oleg Bartunov (oleg@sai.msu.su).



On Sun, 17 Dec 2000, Tom Lane wrote:

> Oleg Bartunov <oleg@sai.msu.su> writes:
> > I checked 7.1 feature list and didn't find any mention about GiST
> > but there are changes in GiST code. Who is a maintainer of GiST code ?
>
> You are ;-).  If you expect to find someone who understands GiST better
> than you, you're probably out of luck.
>
> I recall having made a number of changes that applied to all of the
> index access methods, including GiST --- but I was just changing
> similar code in all the methods.  I don't claim to know anything
> about GiST in particular.
>
>             regards, tom lane
>
Regards,    Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83