diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 128 |
1 files changed, 86 insertions, 42 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 49ca0874677..3143767dc5e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.496 2010/01/15 09:18:58 heikki Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.497 2010/01/19 05:50:18 tgl Exp $ --> <chapter id="functions"> <title>Functions and Operators</title> @@ -13173,12 +13173,12 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); </entry> <entry><type>text</type></entry> <entry>Get last transaction log location received and synced to disk during - streaming recovery. If streaming recovery is still in progress - this will increase monotonically. If streaming recovery has completed - then this value will remain static at the value of the last WAL record - received and synced to disk during that recovery. When the server has - been started without a streaming recovery then the return value will be - InvalidXLogRecPtr (0/0). + streaming recovery. If streaming recovery is still in progress + this will increase monotonically. If streaming recovery has completed + then this value will remain static at the value of the last WAL record + received and synced to disk during that recovery. When the server has + been started without a streaming recovery then the return value will be + InvalidXLogRecPtr (0/0). </entry> </row> <row> @@ -13187,11 +13187,11 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); </entry> <entry><type>text</type></entry> <entry>Get last transaction log location replayed during recovery. - If recovery is still in progress this will increase monotonically. - If recovery has completed then this value will remain static at - the value of the last WAL record applied during that recovery. - When the server has been started normally without a recovery - then the return value will be InvalidXLogRecPtr (0/0). + If recovery is still in progress this will increase monotonically. + If recovery has completed then this value will remain static at + the value of the last WAL record applied during that recovery. + When the server has been started normally without a recovery + then the return value will be InvalidXLogRecPtr (0/0). </entry> </row> </tbody> @@ -13207,19 +13207,25 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); <primary>pg_column_size</primary> </indexterm> <indexterm> - <primary>pg_database_size</primary> + <primary>pg_total_relation_size</primary> </indexterm> <indexterm> - <primary>pg_relation_size</primary> + <primary>pg_table_size</primary> </indexterm> <indexterm> - <primary>pg_size_pretty</primary> + <primary>pg_indexes_size</primary> + </indexterm> + <indexterm> + <primary>pg_database_size</primary> </indexterm> <indexterm> <primary>pg_tablespace_size</primary> </indexterm> <indexterm> - <primary>pg_total_relation_size</primary> + <primary>pg_relation_size</primary> + </indexterm> + <indexterm> + <primary>pg_size_pretty</primary> </indexterm> <table id="functions-admin-dbsize"> @@ -13238,44 +13244,48 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); </row> <row> <entry> - <literal><function>pg_database_size</function>(<type>oid</type>)</literal> + <literal><function>pg_total_relation_size</function>(<type>regclass</type>)</literal> </entry> <entry><type>bigint</type></entry> - <entry>Disk space used by the database with the specified OID</entry> + <entry> + Total disk space used by the table with the specified OID or name, + including all indexes and <acronym>TOAST</> data + </entry> </row> <row> <entry> - <literal><function>pg_database_size</function>(<type>name</type>)</literal> + <literal><function>pg_table_size</function>(<type>regclass</type>)</literal> </entry> <entry><type>bigint</type></entry> - <entry>Disk space used by the database with the specified name</entry> + <entry> + Disk space used by the table with the specified OID or name, + excluding indexes (but including TOAST, free space map, and visibility + map) + </entry> </row> <row> <entry> - <literal><function>pg_relation_size</function>(<parameter>relation</parameter> <type>regclass</type>, <parameter>fork</parameter> <type>text</type>)</literal> + <literal><function>pg_indexes_size</function>(<type>regclass</type>)</literal> </entry> <entry><type>bigint</type></entry> <entry> - Disk space used by the specified fork (<literal>'main'</literal>, - <literal>'fsm'</literal> or <literal>'vm'</>) - of the table or index with the specified OID or name + Total disk space used by indexes attached to the table with the + specified OID or name </entry> </row> <row> <entry> - <literal><function>pg_relation_size</function>(<parameter>relation</parameter> <type>regclass</type>)</literal> + <literal><function>pg_database_size</function>(<type>oid</type>)</literal> </entry> <entry><type>bigint</type></entry> - <entry> - Shorthand for <literal>pg_relation_size(..., 'main')</literal> - </entry> + <entry>Disk space used by the database with the specified OID</entry> </row> <row> <entry> - <literal><function>pg_size_pretty</function>(<type>bigint</type>)</literal> + <literal><function>pg_database_size</function>(<type>name</type>)</literal> </entry> - <entry><type>text</type></entry> - <entry>Converts a size in bytes into a human-readable format with size units</entry> + <entry><type>bigint</type></entry> + <entry>Disk space used by the database with the specified name</entry> </row> <row> <entry> @@ -13293,14 +13303,31 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); </row> <row> <entry> - <literal><function>pg_total_relation_size</function>(<type>regclass</type>)</literal> + <literal><function>pg_relation_size</function>(<parameter>relation</parameter> <type>regclass</type>, <parameter>fork</parameter> <type>text</type>)</literal> </entry> <entry><type>bigint</type></entry> <entry> - Total disk space used by the table with the specified OID or name, - including indexes and <acronym>TOAST</> data + Disk space used by the specified fork (<literal>'main'</literal>, + <literal>'fsm'</literal> or <literal>'vm'</>) + of the table or index with the specified OID or name </entry> </row> + <row> + <entry> + <literal><function>pg_relation_size</function>(<parameter>relation</parameter> <type>regclass</type>)</literal> + </entry> + <entry><type>bigint</type></entry> + <entry> + Shorthand for <literal>pg_relation_size(..., 'main')</literal> + </entry> + </row> + <row> + <entry> + <literal><function>pg_size_pretty</function>(<type>bigint</type>)</literal> + </entry> + <entry><type>text</type></entry> + <entry>Converts a size in bytes into a human-readable format with size units</entry> + </row> </tbody> </tgroup> </table> @@ -13311,6 +13338,26 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); </para> <para> + <function>pg_total_relation_size</> accepts the OID or name of a + table or toast table, and returns the total on-disk space used for + that table, including all associated indexes. This function is + equivalent to <function>pg_table_size</function> + <literal>+</> <function>pg_indexes_size</function>. + </para> + + <para> + <function>pg_table_size</> accepts the OID or name of a table and + returns the disk space needed for that table, exclusive of indexes. + (TOAST space, free space map, and visibility map are included.) + </para> + + <para> + <function>pg_indexes_size</> accepts the OID or name of a table and + returns the total disk space used by all the indexes attached to that + table. + </para> + + <para> <function>pg_database_size</function> and <function>pg_tablespace_size</> accept the OID or name of a database or tablespace, and return the total disk space used therein. @@ -13318,14 +13365,17 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); <para> <function>pg_relation_size</> accepts the OID or name of a table, index or - toast table, and returns the size in bytes. Specifying + toast table, and returns the on-disk size in bytes. Specifying <literal>'main'</literal> or leaving out the second argument returns the size of the main data fork of the relation. Specifying <literal>'fsm'</literal> returns the size of the Free Space Map (see <xref linkend="storage-fsm">) associated with the relation. Specifying <literal>'vm'</literal> returns the size of the Visibility Map (see <xref linkend="storage-vm">) associated with the - relation. + relation. Note that this function shows the size of only one fork; + for most purposes it is more convenient to use the higher-level + functions <function>pg_total_relation_size</> or + <function>pg_table_size</>. </para> <para> @@ -13335,12 +13385,6 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup()); </para> <para> - <function>pg_total_relation_size</> accepts the OID or name of a - table or toast table, and returns the size in bytes of the data - and all associated indexes and toast tables. - </para> - - <para> The functions shown in <xref linkend="functions-admin-genfile"> provide native access to files on the machine hosting the server. Only files within the |