Comment by fsiefken

The Btfrs and Reiser4 filesystems also support transparent compression and might currently be a better alternative to increase Postgresql query speed. Btfrs supports gzip, LZO, LZ4 and Snappy and is in the mainline linux kernel, Reiser4 is still maintained and available as a patch on Linux 3.8.5 (latest is 3.8.8) and supports LZO and gzip (alternatively there are also the embedded NAND flash medium compatible filesystems F2FS and UBIFS which both improve on the JFFS2 filesystem and it's transparent compression). For I/O bound queries SSD drives (in your preferred raid configuration) also will speed up the system. Btfrs has built-in support for TRIM SSD already, Reiser4 TRIM/SSD support is being discussed among the remaining developers.