The 8.1 Release Notes have the following item: * Allow non-consecutive index columns to be used in a multi-column index
So isn't the following paragraph from "Multicolumn Indexes" out of date? The query planner can use a multicolumn index for queries that involve the leftmost column in the index definition plus any number of columns listed to the right of it, without a gap. For example, an index on (a, b, c) can be used in queries involving all of a, b, and c, or in queries involving both a and b, or in queries involving only a, but not in other combinations. (In a query involving a and c the planner could choose to use the index for a, while treating c like an ordinary unindexed column.) http://developer.postgresql.org/docs/postgres/indexes-multicolumn.html -- Michael Fuhr ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
