SQL$HELP72.HLB  —  ALTER  DATABASE  Arguments  CHECKSUM_CALCULATION
    Syntax options:

       CHECKSUM CALCULATION
       SNAPSHOT CHECKSUM CALCULATION

 This option allows you to enable or disable calculations of page
 checksums when pages are read from or written to the storage area or
 snapshot files.

    The default is ENABLED.

                                   NOTE

       Oracle Corporation recommends that you leave checksum
       calculations enabled, which is the default.

    With current technology, it is possible that errors may occur
    that the checksum calculation can detect but that may not
    be detected by either the hardware, firmware, or software.
    Unexpected application results and database corruption may occur
    if corrupt pages exist in memory or on disk but are not detected.

    Oracle Corporation recommends performing checksum calculations,
    except in the following specific circumstances:

    o  Your application is stable and has run without errors on the
       current hardware and software configuration for an extended
       period of time.

    o  You have reached maximum CPU utilization in your current
       configuration. Actual CPU utilization by the checksum
       calculation depends primarily on the size of the database
       pages in your database. The larger the database page, the
       more noticeable the CPU usage by the checksum calculation may
       become.

                                   NOTE

       Oracle Corporation recommends that you carefully evaluate
       the trade-off between reducing CPU usage by the checksum
       calculation and the potential for loss of database integrity
       if checksum calculations are disabled.

    Oracle Corporation allows you to disable and, subsequently,
    re-enable checksum calculation without error. However, once
    checksum calculations have been disabled, corrupt pages may
    not be detected even if checksum calculations are subsequently
    re-enabled.
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