Sami Dalouche <skoobi@xxxxxxx> writes: > So, what could prevent postgrs from using the index ? You've carefully withheld all the details that might let us guess. If I had to guess anyway, I'd guess this is a pre-8.2 PG release that doesn't know how to rearrange outer joins, but there are any number of other possibilities. If you want useful help on a query planning issue, you generally need to provide - the exact Postgres version - full schema declaration of the relevant tables - exact queries tested - full EXPLAIN ANALYZE output With less info than that, people are just shooting in the dark. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match