postgresql pg_xlog is not strictly a circular buffer
August 4th, 2011
Normally, we think that xlog file is like a circular buffer. We write to the same addresses again and again.
However, according to this document, we should see that
Ordinarily, when old log segment files are no longer needed, they are recycled (renamed to become the next segments in the numbered sequence). If, due to a short-term peak of log output rate, there are more than 3 * checkpoint_segments + 1 segment files, the unneeded segment files will be deleted instead of recycled until the system gets back under this limit.
Recent Comments