Friendly greetings ! I'd like to have a higher compression ratio on our base.
>From pg 8.3 documentation : The TOAST code is triggered only when a row value to be stored in a table is wider than TOAST_TUPLE_THRESHOLD bytes (normally 2 kB). The TOAST code will compress and/or move field values out-of-line until the row value is shorter than TOAST_TUPLE_TARGET bytes (also normally 2 kB) or no more gains can be had. According to the source code : TOAST_TUPLE_THRESHOLD = a page (8KB) divided by TOAST_TUPLES_PER_PAGE (4 by default) = 2KB. TOAST_TUPLE_TARGET = TOAST_TUPLE_THRESHOLD = 2KB If i understood correctly, the compression stop when the data to toast is equal to TOAST_TUPLE_TARGET What about trying to change the TOAST_TUPLE_TARGET to get a higher compression (by having more toasted record) ? I'd like to change the TOAST_TUPLES_PER_PAGE. Maybe from 4 to 8 ? Is that correct ? Did i missed something ? I did some statistics and i will have much more TOASTed record as most of them are between 1KB and 2KB. The servers have a lot of free cpu (2x4 core) and are running out of IO, i hope to save some IO. PS : The tables are clustered and all required index are present. Any tought ? idea ? Thank you. -- F4FQM Kerunix Flan Laurent Laborde -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
