Paul Matthews <plm@netspace.net.au> writes:
> The problem is, according to EXPLAIN, it still wants to do a sequential
> scan and not use the index. Any pointers as to why?
Can you force it with enable_seqscan = off? If so, then positionsel
isn't estimating a small enough number of matches to make an indexscan
look useful. (Which, for a "left of" operator, is hardly surprising.)
If not, there's something wrong with your opfamily declarations.
regards, tom lane
