>> > Our WAL files are 16 Mb in size each. I cannot find where you >> > configure them to make them larger. 16 Mb is too small for our
>> > instalation. If necessary, I can rebuild the entire cluster. Our >> > DBA initialized a new cluster and specified a larger WAL size but it >> > stayed at 16 Mb. Any info on this? >> >> Why is 16MB too small? Most people increase checkpoint_segments for >> larger installs and it works fine. >To answer the question, it is possible to change the wal log size. It is >a setting in pg_config.h: #define XLOG_SEG_SIZE (16 * 1024 * 1024) . > >If you change that and recompile, your wal segment size will be >different. I have heard of people running 32meg sizes. We have tried >with smaller sizes but it ended up thrashes the disk. > >Further keep in mind you will have to do a dump and restore to the new >cluster. Your existing cluster will not be usable once you do this. Probably won't change then. The boss was worried that a 16 Mb file size would cause performance issues on a busy database server.
