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>SAVEPOINT</H1
><DIV
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><A
NAME="AEN77394"
></A
><H2
>Name</H2
>SAVEPOINT -- define a new savepoint within the current transaction</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN77402"
></A
><H2
>Synopsis</H2
><PRE
CLASS="SYNOPSIS"
>SAVEPOINT <TT
CLASS="REPLACEABLE"
><I
>savepoint_name</I
></TT
></PRE
></DIV
><DIV
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><A
NAME="AEN77405"
></A
><H2
>Description</H2
><P
> <TT
CLASS="COMMAND"
>SAVEPOINT</TT
> establishes a new savepoint within
the current transaction.
</P
><P
> A savepoint is a special mark inside a transaction that allows all commands
that are executed after it was established to be rolled back, restoring
the transaction state to what it was at the time of the savepoint.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN77410"
></A
><H2
>Parameters</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="REPLACEABLE"
><I
>savepoint_name</I
></TT
></DT
><DD
><P
> The name to give to the new savepoint.
</P
></DD
></DL
></DIV
></DIV
><DIV
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><A
NAME="AEN77418"
></A
><H2
>Notes</H2
><P
> Use <A
HREF="sql-rollback-to.html"
>ROLLBACK TO SAVEPOINT</A
> to
rollback to a savepoint. Use <A
HREF="sql-release-savepoint.html"
>RELEASE SAVEPOINT</A
>
to destroy a savepoint, keeping
the effects of commands executed after it was established.
</P
><P
> Savepoints can only be established when inside a transaction block.
There can be multiple savepoints defined within a transaction.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN77424"
></A
><H2
>Examples</H2
><P
> To establish a savepoint and later undo the effects of all commands executed
after it was established:
</P><PRE
CLASS="PROGRAMLISTING"
>BEGIN;
INSERT INTO table1 VALUES (1);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (2);
ROLLBACK TO SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (3);
COMMIT;</PRE
><P>
The above transaction will insert the values 1 and 3, but not 2.
</P
><P
> To establish and later destroy a savepoint:
</P><PRE
CLASS="PROGRAMLISTING"
>BEGIN;
INSERT INTO table1 VALUES (3);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (4);
RELEASE SAVEPOINT my_savepoint;
COMMIT;</PRE
><P>
The above transaction will insert both 3 and 4.
</P
></DIV
><DIV
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><A
NAME="AEN77430"
></A
><H2
>Compatibility</H2
><P
> SQL requires a savepoint to be destroyed automatically when another
savepoint with the same name is established. In
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>, the old savepoint is kept, though only the more
recent one will be used when rolling back or releasing. (Releasing the
newer savepoint with <TT
CLASS="COMMAND"
>RELEASE SAVEPOINT</TT
> will cause the older one
to again become accessible to <TT
CLASS="COMMAND"
>ROLLBACK TO SAVEPOINT</TT
> and
<TT
CLASS="COMMAND"
>RELEASE SAVEPOINT</TT
>.) Otherwise, <TT
CLASS="COMMAND"
>SAVEPOINT</TT
> is
fully SQL conforming.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN77438"
></A
><H2
>See Also</H2
><A
HREF="sql-begin.html"
>BEGIN</A
>, <A
HREF="sql-commit.html"
>COMMIT</A
>, <A
HREF="sql-release-savepoint.html"
>RELEASE SAVEPOINT</A
>, <A
HREF="sql-rollback.html"
>ROLLBACK</A
>, <A
HREF="sql-rollback-to.html"
>ROLLBACK TO SAVEPOINT</A
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