Most of the time I can get what I want out of SQL using the standard aggregate functions, but today I needed to find the latest timestamp from any one of three columns.

I achieved this using the GREATEST() function, it’s not part of the SQL standard but is commonly available.

I’ve written a patch for Drupal 7 to enable date and time data types to be defined for the schema API.

http://drupal.org/node/200953

Update : it got removed

I’ve just had cause to restore a two year old backup of a database I haven’t used in a whileSince then postgresql (on Debian at least) has added the option to have multiple ‘clusters’ and multple versions running on the same machine.

Fortunately the old version (7.4) was still available

Steps

I’ve just been experimenting with text searches: http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/docs/tsearch-V2-intro.html