Chapter 25. Monitoring Database Activity
A database administrator frequently wonders, "What is the system
doing right now?"
This chapter discusses how to find that out.
Several tools are available for monitoring database activity and
analyzing performance. Most of this chapter is devoted to describing
PostgreSQL's statistics collector,
but one should not neglect regular Unix monitoring programs such as
ps, top, iostat, and vmstat.
Also, once one has identified a
poorly-performing query, further investigation may be needed using
PostgreSQL's EXPLAIN command.
Section 13.1 discusses EXPLAIN
and other methods for understanding the behavior of an individual
query.