> 4. The only reason we need to take relation-level locks on indexes
> at all is to make the world safe for REINDEX being done concurrently
> with read-only accesses to the table (that don't use the index being
> reindexed). If we went back to requiring exclusive lock for reindex we
> could forget all about both #2 and #3. Particularly for updates of
> relations with lots of indexes, this could be a pretty significant win.
> However we'd definitely be giving up something that was seen as a
> feature at one point, so I'm not sold on this idea ... unless someone
> can see a way to reduce the overhead without giving up concurrent
> REINDEX.
Surely in the real world REINDEX is run so rarely compared to all those
other operations it'd be a win...
Chris
