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@ -1,5 +1,5 @@ |
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<!-- |
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$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.274 2005/07/30 14:52:04 momjian Exp $ |
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$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.275 2005/07/30 22:53:15 tgl Exp $ |
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PostgreSQL documentation |
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--> |
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@ -4903,24 +4903,6 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})'); |
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such pair. |
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</para> |
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<para> |
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When adding an <type>interval</type> value to (or subtracting an |
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<type>interval</type> value from) a <type>timestamp with time zone</type> |
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value, the days component advances (or decrements) the date of the |
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<type>timestamp with time zone<type> by the indicated number of days. |
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Across daylight saving time changes (with the session tiem zone set to a |
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time zone that recognizes DST), this means <literal>interval '1 day'</literal> |
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does not necessarily equal <literal>interval '24 hours'</literal>. |
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For example, with the session time zone set to <literal>CST7CDT</literal> |
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<literal>timestamp with time zone '2005-04-02 12:00-07' + interval '1 day' </literal> |
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will produce <literal>timestamp with time zone '2005-04-03 12:00-06'</literal>, |
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while adding <literal>interval '24 hours'</literal> to the same initial |
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<type>timestamp with time zone</type> produces |
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<literal>timestamp with time zone '2005-04-03 13:00-06'</literal>, as there is |
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a change in daylight saving time at <literal>2005-04-03 02:00</literal> in time zone |
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<literal>CST7CDT</literal>. |
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</para> |
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<table id="operators-datetime-table"> |
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<title>Date/Time Operators</title> |
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@ -5241,6 +5223,24 @@ SELECT (DATE '2001-02-16', INTERVAL '100 days') OVERLAPS |
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<lineannotation>Result: </lineannotation><computeroutput>false</computeroutput> |
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</screen> |
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<para> |
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When adding an <type>interval</type> value to (or subtracting an |
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<type>interval</type> value from) a <type>timestamp with time zone</type> |
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value, the days component advances (or decrements) the date of the |
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|
<type>timestamp with time zone</type> by the indicated number of days. |
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|
Across daylight saving time changes (with the session time zone set to a |
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time zone that recognizes DST), this means <literal>interval '1 day'</literal> |
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does not necessarily equal <literal>interval '24 hours'</literal>. |
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|
For example, with the session time zone set to <literal>CST7CDT</literal>, |
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<literal>timestamp with time zone '2005-04-02 12:00-07' + interval '1 day' </literal> |
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will produce <literal>timestamp with time zone '2005-04-03 12:00-06'</literal>, |
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while adding <literal>interval '24 hours'</literal> to the same initial |
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<type>timestamp with time zone</type> produces |
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<literal>timestamp with time zone '2005-04-03 13:00-06'</literal>, as there is |
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a change in daylight saving time at <literal>2005-04-03 02:00</literal> in time zone |
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<literal>CST7CDT</literal>. |
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</para> |
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<sect2 id="functions-datetime-extract"> |
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<title><function>EXTRACT</function>, <function>date_part</function></title> |
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@ -9275,17 +9275,17 @@ SELECT set_config('log_statement_stats', 'off', false); |
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<primary>pg_relation_size</primary> |
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</indexterm> |
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<para> |
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<function>pg_relation_size</> accepts the oid or name of a table, index or |
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toast table, and returns the size in bytes. |
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<function>pg_relation_size</> accepts the oid or name of a table, index or |
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toast table, and returns the size in bytes. |
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</para> |
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<para> |
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<function>pg_complete_relation_size</> accepts the oid or name of a table or |
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toast table, and returns the size in bytes of the data and all associated |
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<function>pg_complete_relation_size</> accepts the oid or name of a table or |
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toast table, and returns the size in bytes of the data and all associated |
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indexes and toast tables. |
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</para> |
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<para> |
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<function>pg_size_pretty</> can be used to format the size of the |
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database objects in a human readable way, using kB, MB, GB or TB as appropriate. |
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<function>pg_size_pretty</> can be used to format the size of the |
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database objects in a human readable way, using kB, MB, GB or TB as appropriate. |
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</para> |
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</sect1> |
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