Re: Save Hash Indexes

Andrew Dunstan <andrew@dunslane.net> writes:
> Yeah, and there's this: I've had at least one client who switched to 
> using hash indexes and got a significant benefit from it precisely 
> because they aren't WAL logged. They could afford to rebuild the indexes 
> in the unlikely event of a crash, but the IO gain was worth it to them. 
> Neither could they have tolerated unlogged tables - they wanted crash 
> safety for their data. After talking through the various options with 
> them they decided this was the best choice, and it might be sad to 
> remove that choice from people.

That's an interesting story, but it seems like what it points to is the
need for a general "unlogged index" feature, rather than depending on
what's universally agreed to be an implementation deficiency of hash
indexes.  So it sounds like an independent topic.
        regards, tom lane