Add section on testing index scan.

23 years ago · d12be5c37b
parent 3c731e0ed7
commit d12be5c37b
1 changed files with 5 additions and 1 deletions
--- a/doc/FAQ
+++ b/doc/FAQ
@ -1,7 +1,7 @@

                Frequently Asked Questions (FAQ) for PostgreSQL
                                       
-   Last updated: Sun Jan 12 13:36:11 EST 2003
+   Last updated: Fri Jan 17 12:15:04 EST 2003
   
   Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
   
@ -749,6 +749,10 @@
    ORDER BY col [ DESC ]
    LIMIT 1;

+   If you believe the optimizer is incorrect in choosing a sequential
+   scan, use SET enable_seqscan TO 'off' and run tests to see if an index
+   scan is indeed faster.
+   
   When using wild-card operators such as LIKE or ~, indexes can only be
   used in certain circumstances:
     * The beginning of the search string must be anchored to the start