Pete Yunker <peter.yunker@homejunction.com> writes:
> Would a simple multi-column index be considered an 'expression' in this context, meaning that an ANALYZE should be
issuedafter the creation of such an index?
No. Of course, if one of its columns were an expression, then that would
be of interest for ANALYZE.
There has been some talk of collecting column-correlation statistics for
sets of columns listed in multi-column indexes. So it's possible that in
some future PG version, creating a multi-column index will be a reason to
re-ANALYZE. But it isn't today.
regards, tom lane