mirror of https://github.com/postgres/postgres
Add section on testing index scan.
This commit is contained in:
parent
3c731e0ed7
commit
d12be5c37b
6
doc/FAQ
6
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
|
||||
|
|
Loading…
Reference in New Issue