Sophie: postgresql8.3-docs-8.3.8-1mdv2010.0 i586

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><A
NAME="RUNTIME-CONFIG-LOCKS"
>18.11. Lock Management</A
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><DT
><A
NAME="GUC-DEADLOCK-TIMEOUT"
></A
><TT
CLASS="VARNAME"
>deadlock_timeout</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
>        This is the amount of time, in milliseconds, to wait on a lock
        before checking to see if there is a deadlock condition. The
        check for deadlock is relatively slow, so the server doesn't run
        it every time it waits for a lock. We optimistically assume
        that deadlocks are not common in production applications and
        just wait on the lock for a while before starting the check for a
        deadlock. Increasing this value reduces the amount of time
        wasted in needless deadlock checks, but slows down reporting of
        real deadlock errors. The default is one second (<TT
CLASS="LITERAL"
>1s</TT
>),
        which is probably about the smallest value you would want in
        practice. On a heavily loaded server you might want to raise it.
        Ideally the setting should exceed your typical transaction time,
        so as to improve the odds that a lock will be released before
        the waiter decides to check for deadlock.
       </P
><P
>        When <A
HREF="runtime-config-logging.html#GUC-LOG-LOCK-WAITS"
>log_lock_waits</A
> is set,
        this parameter also determines the length of time to wait before
        a log message is issued about the lock wait.  If you are trying
        to investigate locking delays you might want to set a shorter than
        normal <TT
CLASS="VARNAME"
>deadlock_timeout</TT
>.
       </P
></DD
><DT
><A
NAME="GUC-MAX-LOCKS-PER-TRANSACTION"
></A
><TT
CLASS="VARNAME"
>max_locks_per_transaction</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
>        The shared lock table is created to track locks on
        <TT
CLASS="VARNAME"
>max_locks_per_transaction</TT
> * (<A
HREF="runtime-config-connection.html#GUC-MAX-CONNECTIONS"
>max_connections</A
> + <A
HREF="runtime-config-resource.html#GUC-MAX-PREPARED-TRANSACTIONS"
>max_prepared_transactions</A
>) objects (e.g.  tables);
        hence, no more than this many distinct objects can be locked at
        any one time.  This parameter controls the average number of object
        locks allocated for each transaction;  individual transactions
        can lock more objects as long as the locks of all transactions
        fit in the lock table.  This is <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not</I
></SPAN
> the number of
        rows that can be locked; that value is unlimited.  The default,
        64, has historically proven sufficient, but you might need to
        raise this value if you have clients that touch many different
        tables in a single transaction. This parameter can only be set at
        server start.
       </P
><P
>        Increasing this parameter might cause <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
        to request more <SPAN
CLASS="SYSTEMITEM"
>System V</SPAN
> shared
        memory than your operating system's default configuration
        allows. See <A
HREF="kernel-resources.html#SYSVIPC"
>Section 17.4.1</A
> for information on how to
        adjust those parameters, if necessary.
       </P
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