102 ms·
You mean how the transaction rate changes when things like checkpoint or vacuum are triggered in the background? Yeah, I do have those numbers, and the consiste
by pgaddict 12y ago
You mean how the transaction rate changes when things like checkpoint or vacuum are triggered in the background? Yeah, I do have those numbers, and the consistency improved a lot (especially when autovacuum was introduced in 8.1, and when spread checkpoints were introduced in 8.3).
The other part of the story are filesystems - back in 8.x days the filesystem was usually ext3, and that handled sync pretty badly (and that made the impact of checkpoints / autovacuum much worse). Today we have xfs/ext4 which do handle that much better.
- morgo 12y agoCheckpoint and vacuum are good examples. There are other stalls we have had to address: extending the size of tablespace files, dropping tables and scanning the LRU to free pages.
- pgaddict 12y agoPostgreSQL stores the data in a different way (each object gets a different file, or several files), so extending the size of tablespace files is not a big issue and dropping objects is as simple as deleting the file. The LRU is basically the shared_buffers, and that's where most of the 9.2 improvements were (more or less).