> > the multi-segment indexes are to optimize commonly used queries.
>
> In this case you can consider removing one or two fields from the index and
> see how much selectivity it lose and how much performance would be
> affected.

So, you are saying that having less fields reduces the index depth? (I always thought the reverse)

Measuring performance impact will be difficult to do, I don't have details of all cases where one index may be used over another.

Reducing number of columns would mean more row reads, no?

FYI, our deployments use FB 2.5 Classic (we have a some installs with very large number of DB connections) so large FB page cache is not possible.


Sean