Le 18/05/2015 17:20, William Dunn a écrit : Hello William,
Hello François - the CLUSTER command doesn't have to do with where your indexes are. What the CLUSTER command does is physically sort the table data based on the index (Doc: http://www.postgresql.org/docs/devel/static/sql-cluster.html). So for example if you have a column called 'region_code' with an index and CLUSTER the table by that index all the rows for 'region_code'=15 will be located next to each other on disk and can be read in the same IO operation. The usual disadvantage of CLUSTER is that it does not maintain itself, but since your data is read-only that doesn't matter. And yes you can still have the index on an SSD and the source table on slower storage.
My bad, got it. May be interesting but as I have a lot of indexes it will be hard to test and to choose the best candidate. No idea of how it can affect EWKB data indexed by a GiST (PostGIS) index, but it's something to try just to know.
Thanks a lot, may be I will be able to do something with that! Best regards -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
