2015-03-08 10:04 GMT+01:00 Nicolas Paris <nipari...@gmail.com>: > Thanks. > > Then, > Is it a good idea to run multiple instance of "create index on tableX" on > the same time ? Or is it better to do it sequentially ? > In other words : Can one seq scan on a table benefit to multiple create > index stmt on that table ? > > It usually is a good idea to parallelize index creation. That's one of the good things that pg_restore does since the 8.4 release.
Nicolas PARIS > > 2015-03-07 12:56 GMT+01:00 Guillaume Lelarge <guilla...@lelarge.info>: > >> Le 7 mars 2015 11:32, "Nicolas Paris" <nipari...@gmail.com> a écrit : >> > >> > Hello, >> > >> > I wonder if the process of index creation can benefit from other >> indexes. >> > >> >> It cannot. >> >> > EG: Creating a partial index with predicat based on a boolean column, >> will use an hypothetic index on that boolean column or always use a seq >> scan on all rows ? >> > >> >> Nope, it always does a seqscan. >> >> > Goal is to create partial indexes faster. >> > >> > Explain command does not work with Create index. >> > >> >> You cannot use EXPLAIN on most DDL commands. >> > > -- Guillaume. http://blog.guillaume.lelarge.info http://www.dalibo.com
