Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.sai.msu.su/~megera/postgres/gist/code/7.1/README.gist Дата изменения: Wed Jan 10 14:56:13 2001 Дата индексирования: Sat Dec 22 07:48:34 2007 Кодировка:

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 Search Trees for Database Systems". This (old)
algorithm was not suitable for variable size keys and could be
not effective ( 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 decompression function
does real job.
2. NULLs handling - we keep NULLs in tree. Right way is to remove them,
but we don't know how to inform vacuum about index statistics. This is
just cosmetic warning message (like in case with R-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).