[PATCHES] GIN improvements

Improvements of GIN indexes were presented on PGCon 2008. Presentation: http://www.sigaev.ru/gin/fastinsert_and_multicolumn_GIN.pdf 1) multicolumn GIN This patch ( http://www.sigaev.ru/misc/multicolumn_gin-0.2.gz ) adds multicolumn support to GIN. The basic idea is: keys (entries in GIN termin

[PATCHES] partial header cleanup

This replace xlog.h with xlogdefs.h in bufpage.h. All other changes are forgotten include somewhere. It reduce e.g. bloat to half in itup.h. But, There are still unresolved problems. htup should include bufpage.h, because it needs PageHeader size, but there is still unnecessary bufmgr.h include