Database

http://www.sql.ru/forum/actualthread.aspx?tid=499910 simple tree for cascade menues in postgers

http://okbob.blogspot.com/2007/11/stacked-recordset-multirecordset.html multi-records set and cross-table queries

http://gavinroy.com/2007/10/6/first-impressions-of-plproxy notes on Pl/Proxy (interdatabase connectivity for stored prosedures )

http://archives.postgresql.org/pgsql-general/2003-07/msg01507.php how to convert hex to decimal in Postgres

http://poorbuthappy.com/ease/archives/2007/04/29/3616/the-top-10-presentation-on-scaling-websites-twitter-flickr-bloglines-vox-and-more a collection of presentation on hi loaded web apps and their architecture

http://www.livejournal.com/doc/server/ljp.dbschema.ref.html basically raw schema in html with some comments

http://postgrestips.blogspot.com/2007/06/blog-post.html Some tips (in russian) on postgresql programming

http://www.spinics.net/lists/pgsql/msg62574.html sort of official note that slony-II died (project never shipped any code)

http://dammit.lt/2007/01/26/mysql-covering-index-performance/ mysql index performance tech internals (interesting)

http://www.planetpostgresql.org/ blog where postgresql developers post stuff