diff --git a/doc/FAQ b/doc/FAQ
index 63dcc904e7..2fe694b717 100644
--- a/doc/FAQ
+++ b/doc/FAQ
@@ -1,7 +1,7 @@
Frequently Asked Questions (FAQ) for PostgreSQL
- Last updated: Sun Jan 30 21:44:35 EST 2005
+ Last updated: Mon Jan 31 15:40:24 EST 2005
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
@@ -346,41 +346,41 @@
By default, PostgreSQL only allows connections from the local machine
using Unix domain sockets or TCP/IP connections. Other machines will
not be able to connect unless you modify listen_addresses in the
- postgresql.conf and enable host-based authentication by modifying the
- file $PGDATA/pg_hba.conf accordingly.
+ postgresql.conf file, enable host-based authentication by modifying
+ the $PGDATA/pg_hba.conf file, and restart the server.
3.3) How do I tune the database engine for better performance?
- Certainly, indexes can speed up queries. The EXPLAIN ANALYZE command
- allows you to see how PostgreSQL is interpreting your query, and which
- indexes are being used.
-
- If you are doing many INSERTs, consider doing them in a large batch
- using the COPY command. This is much faster than individual INSERTS.
- Second, statements not in a BEGIN WORK/COMMIT transaction block are
- considered to be in their own transaction. Consider performing several
- statements in a single transaction block. This reduces the transaction
- overhead. Also, consider dropping and recreating indexes when making
- large data changes.
-
- There are several tuning options in the Administration Guide/Server
- Run-time Environment/Run-time Configuration. You can disable fsync()
- by using fsync option. This will prevent fsync()s from flushing to
- disk after every transaction.
-
- You can use the shared_buffers option to increase the number of shared
- memory buffers used by the backend processes. If you make this
- parameter too high, the postmaster may not start because you have
- exceeded your kernel's limit on shared memory space. Each buffer is 8K
- and the default is 1000 buffers.
-
- You can also use the sort_mem (from PostgreSQL 8.0: work_mem) options
- to increase the maximum amount of memory used by the backend processes
- for each temporary sort. The default is 1024 (i.e. 1MB).
-
- You can also use the CLUSTER command to group data in tables to match
- an index. See the CLUSTER manual page for more details.
+ There are three major areas for potential performance improvement:
+ Query Changes
+ This involves modifying queries to obtain better performance:
+
+ + Creation of indexes, including expression and partial indexes
+ + Use of COPY instead of multiple INSERTs
+ + Grouping of multiple statements into a single transaction to
+ reduce commit overhead
+ + Use of CLUSTER when retrieving many rows from an index
+ + Use of LIMIT for returning a subset of a query's output
+ + Use of Prepared queries
+ + Use of ANALYZE to maintain accurate optimizer statistics
+ + Regular use of VACUUM or pg_autovacuum
+ + Dropping of indexes during large data changes
+
+ Server Configuration
+ A number of postgresql.conf settings affect performance. For
+ more details, see Administration Guide/Server Run-time
+ Environment/Run-time Configuration for a full listing, and for
+ commentary see
+ http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_co
+ nf_e.html and
+ http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html.
+
+ Hardware Selection
+ The effect of hardware on performance is detailed in
+ http://candle.pha.pa.us/main/writings/pgsql/hw_performance/inde
+ x.html.
+
3.4) What debugging features are available?
PostgreSQL has several features that report status information that
diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html
index fadb993467..8ea5f32443 100644
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -10,7 +10,7 @@
alink="#0000ff">
Frequently Asked Questions (FAQ) for PostgreSQL
- Last updated: Sun Jan 30 21:44:35 EST 2005
+ Last updated: Mon Jan 31 15:40:24 EST 2005
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
@@ -428,8 +428,8 @@
RHDB Admin (http://sources.redhat.com/rhd
b/ ), TORA (http://www.globecom.net/tora/, partly commercial), and Rekall (http://www.globecom.net/tora/,
+ partly commercial), and Rekall (
http://www.rekallrevealed.org/). There is also PhpPgAdmin (
@@ -457,48 +457,64 @@
By default, PostgreSQL only allows connections from the local
machine using Unix domain sockets or TCP/IP connections. Other
machines will not be able to connect unless you modify
- listen_addresses in the postgresql.conf and enable
- host-based authentication by modifying the file
- $PGDATA/pg_hba.conf accordingly.
+ listen_addresses in the postgresql.conf file, enable
+ host-based authentication by modifying the
+ $PGDATA/pg_hba.conf file, and restart the server.
3.3) How do I tune the database engine for
better performance?
- Certainly, indexes can speed up queries. The
- EXPLAIN ANALYZE command allows you to see how
- PostgreSQL is interpreting your query, and which indexes are
- being used.
+ There are three major areas for potential performance
+ improvement:
+
+
+ - Query Changes
- If you are doing many INSERTs, consider doing
- them in a large batch using the COPY command. This
- is much faster than individual INSERTS. Second,
- statements not in a BEGIN WORK/COMMIT transaction
- block are considered to be in their own transaction. Consider
- performing several statements in a single transaction block. This
- reduces the transaction overhead. Also, consider dropping and
- recreating indexes when making large data changes.
+ - This involves modifying queries to obtain better
+ performance:
+
+ - Creation of indexes, including expression and partial
+ indexes
+ - Use of COPY instead of multiple INSERTs
+ - Grouping of multiple statements into a single transaction to
+ reduce commit overhead
+ - Use of CLUSTER when retrieving many rows from an
+ index
+ - Use of LIMIT for returning a subset of a query's
+ output
+ - Use of Prepared queries
+ - Use of ANALYZE to maintain accurate optimizer
+ statistics
+ - Regular use of VACUUM or pg_autovacuum
+
- Dropping of indexes during large data changes
+
+
+
- There are several tuning options in the Server Configuration
+
+ - A number of postgresql.conf settings affect performance.
+ For more details, see
- Administration Guide/Server Run-time Environment/Run-time Configuration.
- You can disable fsync() by using fsync option. This will
- prevent fsync()s from flushing to disk after every
- transaction.
+ Administration Guide/Server Run-time Environment/Run-time
+ Configuration for a full listing, and for commentary see
+ http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html
+ and
+ http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html.
+
+
+
- You can use the shared_buffers option to
- increase the number of shared memory buffers used by the backend
- processes. If you make this parameter too high, the
- postmaster may not start because you have exceeded your
- kernel's limit on shared memory space. Each buffer is 8K and the
- default is 1000 buffers.
+ - Hardware Selection
- You can also use the sort_mem (from PostgreSQL 8.0: work_mem)
- options to increase the maximum amount of memory used by the backend
- processes for each temporary sort. The default is 1024 (i.e. 1MB).
-
- You can also use the CLUSTER command to group
- data in tables to match an index. See the CLUSTER
- manual page for more details.
+ - The effect of hardware on performance is detailed in
+ http://candle.pha.pa.us/main/writings/pgsql/hw_performance/index.html.
+
+
+
+
3.4) What debugging features are
available?
@@ -1196,5 +1212,3 @@ BYTEA bytea variable-length byte array (null-byte safe)
compiler compute the dependencies automatically.