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CPI4333 - Hashing algorithm used to process join. ( OS/400 )

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Message : CPI4333
Hashing algorithm used to process join.

Message Long Text :

Cause . . . . . : The hash join method is typically used for longer running join queries. The original query will be subdivided into hash join steps.
Each hash join step will be optimized and processed separately. Debug messages which explain the implementation of each hash join step follow this message in the joblog.
The list below shows the names of the files or the table functions used in this query. If the entry is for a file, the format of the entry in this list is the number of the hash join step, the filename as specified in the query, the member name as specified in the query, the filename actually used in the hash join step, and the member name actually used in the hash join step. If the entry is for a table function, the format of the entry in this list is the number of the hash join step and the function name as specified in the query.
&1
&2
&3
&4
&5
&6
&7
&8
&9
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&32
If there are two or more files or functions listed for the same hash step, then that hash step is implemented with nested loop join.
Recovery . . . : The hash join method is usually a good implementation choice, however, if you want to disallow the use of this method specify ALWCPYDTA(*YES).
Refer to the DB2 for i - Database Performance and Query Optimization topic collection in the Database category in the IBM i Information Center for more information on hashing algorithm for join processing.

Message File : QCPFMSG
Library Message File : QSYS2924


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