"Andrei Bintintan" <[EMAIL PROTECTED]> writes: > Hi to all! I have the following query. The execution time is very big, it > doesn't use the indexes and I don't understand why...
Indexes are not necessarily the best way to do a large join. > If I use the following query the indexes are used: The key reason this wins seems to be that the id_status = 4 condition is far more selective than id_status > 3 (the estimates are 52 and 36967 rows respectively ... is that accurate?) which means that the second query is inherently about 1/700th as much work. This, and not the use of indexes, is the fundamental reason why it's faster. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster