- publishing free software manuals
PostgreSQL Reference Manual - Volume 1 - SQL Language Reference
by The PostgreSQL Global Development Group
Paperback (6"x9"), 716 pages
ISBN 0954612027
RRP £32.00 ($49.95)

Sales of this book support the PostgreSQL project! Get a printed copy>>>

9.9 Examining Index Usage

Although indexes in PostgreSQL do not need maintenance and tuning, it is still important to check which indexes are actually used by the real-life query workload. Examining index usage for an individual query is done with the EXPLAIN command; its application for this purpose is illustrated in section 11.1 Using EXPLAIN. It is also possible to gather overall statistics about index usage in a running server, as described in Volume 3: The Statistics Collector.

It is difficult to formulate a general procedure for determining which indexes to set up. There are a number of typical cases that have been shown in the examples throughout the previous sections. A good deal of experimentation will be necessary in most cases. The rest of this section gives some tips for that.

ISBN 0954612027PostgreSQL Reference Manual - Volume 1 - SQL Language ReferenceSee the print edition