purge compression dictionary arguments: Remove compression dictionaries (SQL administration API)

Call the admin() or task() function with the compression purge_dictionary initial command to delete all inactive compression dictionaries or all inactive compression dictionaries that were created for a compressed table or fragment before a specified date. You must uncompress tables and fragments, which makes the dictionaries inactive, before you delete any compression dictionaries that were created for the tables and fragments.

Syntax: Compression Purge_Dictionary

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>>-EXECUTE FUNCTION--+-admin-+--(--"--compression purge_dictionary--"--,--"--date--"--)-- ;-><
                     '-task--'                                                                

Usage

Before you perform a purge_dictionary operation for tables and fragments, you must:

  • Uncompress the tables and fragments.

    When you uncompress a table or fragment, Informix® marks the dictionary for the table or fragment as inactive.

  • Be sure that Enterprise Replication functions do not need the compression dictionaries.
  • Archive any dbspace that contains a table or fragment with a compression dictionary, even if you have uncompressed data in the table or fragment and the dictionary is no longer active.

The compression purge_dictionary command deletes all compression dictionaries.

The compression purge_dictionary command with a date as the second argument deletes all compression dictionaries that were created before and on a specified date. You can use any date in a format that can be converted to a DATE data type based on your locale and environment. For example, you can specify 03/29/2009, 03/29/09, or Mar 29, 2009.

You can also delete a specific compression dictionary by calling the admin() or task() function with table or fragment as the initial command and purge_dictionary as the next argument.

You cannot delete compression dictionaries that were created for indexes. The database server removes these compression dictionaries when the indexes are dropped.

The following command tells Informix to remove all dictionaries that were created before and on July 8, 2009:

EXECUTE FUNCTION task(“compression purge_dictionary”, "07/08/2009");

The following command tells Informix to remove the inactive dictionary for a table named auto in the insurance database of which tjones is the owner.

EXECUTE FUNCTION task(“table purge_dictionary", 
“auto”, “insurance”, “tjones”);

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