On Wed, Jun 26, 2013 at 11:14 AM, Claudio Freire <klaussfre...@gmail.com>wrote:
> > Now I just have two indices. One that indexes only hot tuples, it's > very heavily queried and works blazingly fast, and one that indexes by > (hotness, key). I include the hotness value on the query, and still > works quite fast enough. Luckily, I know things become cold after an > update to mark them cold, so I can do that. I included hotness on the > index to cluster updates on the hot part of the index, but I could > have just used a regular index and paid a small price on the updates. > Indeed, for a while it worked without the hotness, and there was no > significant trouble. I later found out that WAL bandwidth was > noticeably decreased when I added that hotness column, so I did, helps > a bit with replication. Has worked ever since. > I'm surprised that clustering updates into the hot part of the index, without also clustering them it into a hot part of the table heap, works well enough to make a difference. Does clustering in the table just come naturally under your usage patterns? Cheers, Jeff
