15.00 - Ferret Commands - Teradata Database

Teradata Database Utilities

Teradata Database
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Ferret Commands

Ferret gives you a wide range of commands that allow you to display specific information about the Teradata Database system, and optimize the system to improve performance. Use Ferret commands to:

  • Define the level or scope of a command, such as a range of tables, vprocs, cylinders, or the WAL log.
  • Display the parameters and scope of a previous action.
  • Perform an action to increase performance, such as moving data to reconfigure data blocks and cylinders.
  • Displaying utilization of storage space by percentage and cylinders.
  • Defining Command Parameters Using SCOPE

    Some Ferret commands require that you first define the parameters, or scope, of the action you want to initiate.

    The SCOPE command allows you to limit the command action in the following areas:


    SCOPE Parameter



  • A single vproc
  • A range of vprocs
  • All vprocs in a configuration

  • A single cylinder
  • A set of cylinders

  • A single table
  • A set of tables
  • All tables in the system
  • A class of tables
  • WAL

    The WAL log

    For more information, see “SCOPE” on page 591.

    Summary of Ferret Commands

    The following table summarizes the Ferret commands, their valid scopes, and gives a brief description of the function of each command:



    Valid SCOPE Options



    Not Applicable

    Compresses data blocks of a specified table, or shows an estimate of what results would be if tables were compressed.



    Displays the current system day, date, and time.


    Vprocs or tables

    Combines free sectors, and moves them to the end of a cylinder.



    Sets a specific flag in the file system to FALSE, disabling certain features of Ferret. Most such flags are for internal use only.



    Sets a specific flag in the file system to TRUE, enabling certain features of Ferret. Most such flags are for internal use only.



    Redirects diagnostic messages to a file that you specify or to the default file STDERR.

    Using the ERRORS command, you can append an existing message file, overwrite an existing message file, write only to a new file, or display the current diagnostic message file.



    Sets the cylinders occupied by a table or range of rows, to a specified temperature, regardless of how frequently the data has been historically accessed.



    Provides general help for Ferret or detailed help if you specify an option or parameter.



    Informs Ferret to read commands from a specified file rather than from the default input file STDIN.



    Redirects Ferret output to a file you specify or to the default file STDOUT.


    Vprocs or tables

    Reconfigures cylinders within a defined scope.



    Sets the priority class of the Ferret process.



    Ends a Ferret session.



    Sets the default radix used as the numeric base for Ferret data input and output.



    Resets the count of running COMPRESS and UNCOMPRESS tasks to zero.


    WAL log, vprocs, or tables

    Performs a verification of the file system B-Tree structure.



    Defines the scope for subsequent DEFRAGMENT, PACKDISK, SCANDISK, SHOWBLOCKS, SHOWFSP, SHOWSPACE, and SHOWWHERE commands.



    Displays which compress and uncompress operations that happen during system recovery to minimize transaction recovery time after a restart.


    WAL log, vprocs, or tables

    Displays data block size and the number of rows per data block for a defined scope. Also indicates whether data blocks use block-level compression.


    Vprocs, and PERMANENT and JRNL tables

    Lists subtables that have data blocks using block-level compression.



    Displays the current default radix for input and output, the current input, output, and error file names, and the current scope settings.


    Vprocs or tables

    Displays table names and space utilization for those tables that would free or consume some number of cylinders if PACKDISK is executed at a particular FSP. The scope can include one or more tables, one or more vprocs, or the entire system.


    WAL log, vprocs, or tables

    Displays storage space utilization for permanent, spool, WAL log, temporary, and journal data, including the amount of free space remaining.


    Vprocs, tables, or WAL log

    Displays information about cylinder allocation and temperature for cylinders in the currently set scope.



    Displays the table number of the specified table when given the database name and table name.


    Not Applicable

    Uncompresses data blocks of a specified table, or shows an estimate of what results would be if tables were uncompressed.



    Updates the data integrity checksum level of a table type.

    The following Ferret commands are used with Teradata Virtual Storage, a storage product available from Teradata. These commands are available only if you have purchased Teradata Virtual Storage, and have appropriate licenses. For more information about these commands, see Teradata Virtual Storage:

  • Ferret Error Messages

    All Ferret error messages are directed by default to your system console screen.

    Ferret and file system error messages can be redirected through use of the ERRORS command.

    For more information on file system messages, see Messages.