diff options
Diffstat (limited to 'doc/src/sgml/ref/alter_sequence.sgml')
| -rw-r--r-- | doc/src/sgml/ref/alter_sequence.sgml | 138 |
1 files changed, 35 insertions, 103 deletions
diff --git a/doc/src/sgml/ref/alter_sequence.sgml b/doc/src/sgml/ref/alter_sequence.sgml index f12e9ad85a0..f4b114da4bd 100644 --- a/doc/src/sgml/ref/alter_sequence.sgml +++ b/doc/src/sgml/ref/alter_sequence.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_sequence.sgml,v 1.3 2003/08/31 17:32:21 petere Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_sequence.sgml,v 1.4 2003/09/09 18:28:52 tgl Exp $ PostgreSQL documentation --> @@ -23,24 +23,27 @@ PostgreSQL documentation </indexterm> <refsynopsisdiv> - <refsynopsisdivinfo> - <date>1999-07-20</date> - </refsynopsisdivinfo> <synopsis> ALTER SEQUENCE <replaceable class="parameter">seqname</replaceable> [ INCREMENT [ BY ] <replaceable class="parameter">increment</replaceable> ] [ MINVALUE <replaceable class="parameter">minvalue</replaceable> | NO MINVALUE ] [ MAXVALUE <replaceable class="parameter">maxvalue</replaceable> | NO MAXVALUE ] [ RESTART [ WITH ] <replaceable class="parameter">start</replaceable> ] [ CACHE <replaceable class="parameter">cache</replaceable> ] [ [ NO ] CYCLE ] </synopsis> - - <refsect2 id="R2-SQL-ALTERSEQUENCE-1"> - <refsect2info> - <date>1998-09-11</date> - </refsect2info> - <title> - Inputs - </title> - <para> + </refsynopsisdiv> + <refsect1> + <title>Description</title> + + <para> + <command>ALTER SEQUENCE</command> changes the parameters of an existing + sequence generator. Any parameter not specifically set in the + <command>ALTER SEQUENCE</command> command retains its prior setting. + </para> + </refsect1> + + <refsect1> + <title>Parameters</title> + + <para> <variablelist> <varlistentry> <term><replaceable class="parameter">seqname</replaceable></term> @@ -100,8 +103,8 @@ ALTER SEQUENCE <replaceable class="parameter">seqname</replaceable> [ INCREMENT <listitem> <para> The optional <option>RESTART WITH - <replaceable class="parameter">start</replaceable> - clause</option> enables the sequence to re-begin anywhere. + <replaceable class="parameter">start</replaceable></option> + clause changes the current value of the sequence. </para> </listitem> </varlistentry> @@ -151,78 +154,11 @@ ALTER SEQUENCE <replaceable class="parameter">seqname</replaceable> [ INCREMENT </varlistentry> </variablelist> </para> - </refsect2> - - <refsect2 id="R2-SQL-ALTERSEQUENCE-2"> - <refsect2info> - <date>1998-09-11</date> - </refsect2info> - <title> - Outputs - </title> - <para> - - <variablelist> - <varlistentry> - <term><computeroutput> -ALTER SEQUENCE - </computeroutput></term> - <listitem> - <para> - Message returned if the command is successful. - </para> - </listitem> - </varlistentry> - <varlistentry> - <term><computeroutput> -ERROR: AlterSequence: MINVALUE (<replaceable class="parameter">start</replaceable>) can't be >= MAXVALUE (<replaceable class="parameter">max</replaceable>) - </computeroutput></term> - <listitem> - <para> - If the specified starting value is out of range. - </para> - </listitem> - </varlistentry> - <varlistentry> - <term><computeroutput> -ERROR: AlterSequence: START value (<replaceable class="parameter">start</replaceable>) can't be < MINVALUE (<replaceable class="parameter">min</replaceable>) - </computeroutput></term> - <listitem> - <para> - If the specified starting value is out of range. - </para> - </listitem> - </varlistentry> - <varlistentry> - <term><computeroutput> -ERROR: AlterSequence: MINVALUE (<replaceable class="parameter">min</replaceable>) can't be >= MAXVALUE (<replaceable class="parameter">max</replaceable>) - </computeroutput></term> - <listitem> - <para> - If the minimum and maximum values are inconsistent. - </para> - </listitem> - </varlistentry> - </variablelist> - </para> - </refsect2> - </refsynopsisdiv> + </refsect1> - <refsect1 id="R1-SQL-ALTERSEQUENCE-1"> - <title> - Description - </title> - - <para> - See <xref linkend="SQL-CREATESEQUENCE"> for limitations, and uses - of sequences. - </para> - </refsect1> + <refsect1> + <title>Examples</title> - <refsect1 id="R1-SQL-ALTERSEQUENCE-2"> - <title> - Usage - </title> <para> Restart a sequence called <literal>serial</literal>, at 105: </para> @@ -231,35 +167,31 @@ ALTER SEQUENCE serial RESTART WITH 105; </programlisting> </refsect1> - <refsect1 id="R1-SQL-ALTERSEQUENCE-5"> - <title> - Notes - </title> + <refsect1> + <title>Notes</title> + <para> - To avoid blocking of concurrent transactions that obtain numbers from the same - sequence, a nextval operation is never rolled back; that is, once a value has - been fetched it is considered used, even if the transaction that did the nextval - later aborts. This means that aborted transactions may leave unused "holes" in - the sequence of assigned values. setval operations are never rolled back, either. + To avoid blocking of concurrent transactions that obtain numbers from the + same sequence, <command>ALTER SEQUENCE</command> is never rolled back; + the changes take effect immediately and are not reversible. </para> + <para> - <command>ALTER SEQUENCE</command> will not immediately affect backends, other than the - current one, which have cached sequence values. They must use up all cached values - prior to noticing the changed sequence parameters. The current backend will be - immediatly affected. + <command>ALTER SEQUENCE</command> will not immediately affect + <literal>nextval</> results in backends, + other than the current one, that have preallocated (cached) sequence + values. They will use up all cached values prior to noticing the changed + sequence parameters. The current backend will be affected immediately. </para> </refsect1> - <refsect1 id="R1-SQL-ALTERSEQUENCE-3"> + <refsect1> <title> Compatibility </title> - <refsect2 id="R2-SQL-ALTERSEQUENCE-4"> - <refsect2info> - <date>2003-03-02</date> - </refsect2info> + <refsect2> <title> SQL99 </title> |