Bruce Momjian wrote:
> > Also, I am wondering whether the information that which index is used to
> > fetch a tuple is always available. I haven't checked, but do we have that
> > information in lossy bitmap heapscan ?
>
> Oh, that is an interesting problem because an index might have one index
> entry representing an entire HOT chain, while another index might
> represent each chain member by individual index entries. When we do the
> bitmaps, don't we access them by heap tid, meaning we would find all
> entries anyway?
I thinking some more, it would be a problem because while we are merging
the tids, we are using index entries and haven't looked at the heap yet.
I am guessing we would have to exclude the new index from bitmap joins
with other indexes until the VACUUM happens.
-- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB
http://www.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
