Using the Product in a DB2 Environment › Explain Function › Display Messages

Display Messages

Type I in the LC field on the DB2 Statements panel and press Enter.

The Explain Information panel displays.

 CA MAT ----------------------- Explain Information ------------- Row 1 to 20
 COMMAND ===>                                               SCROLL ===> HALF

         DBRM name: D91PROG                                   Profile: PROFT9
         Statement: 769                                      DB2 SSID: DIA3
         Stmt type: DECLARE                                   DB2 Rel: 9.1.0

     Line commands: H - Display Help Text

 LC Rule Text
    
___________________________________________________________________________
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 __ TE0000 Step No. 1 is accessing RDWM91.DB2DATA.
 __ TE0002 This table is not being accessed with an index.
 __ TE0003 This is the first table in the query.
 __ TE0011 The table will be accessed using a tablespace scan.Every pagein the
    tablespace will be scanned by DB2 to provide an answer.
 __ TE0012 Note: Unless this statement is retrieving most of the rows in this
    table, consider adding an index on the most restrictive columns in the
    predicate. Examine the columns in the indexes on this table and add them o
    the predicate if possible.
 __ TE0026 The table data pages will be accessed to satisfy this portion of he
    query. This requires additional overhead.
 __ TE0043 The data will be retrieved using Sequential Prefetch.
 __ TE0046 Column function evaluation is not used OR column function evaluation
    will be determined at execution time.
 __ TE0000 Step No. 2 is accessing RDWM91.DB2PART.
 __ TE0002 This table is not being accessed with an index.
 __ TE0007 This table is being accessed using a Merge Scan Join. The composite
    table and the new table are scanned in the order of the join columns and are
    joined for matching rowss.
 __ TE0008 MERGE SCAN: Both tables have groups of duplicates on the join column.
    The composite table has an index on the join column, eliminating the sort.
    The table with fewer qualified rows/columns is the new table.
 __ TE0011 The table will be accessed using a tablespace scan. Every page in the
    tablespace will be scanned by DB2 to provide an answer.
 __ TE0012 Note: Unless this statement is retrieving most of the rows in this
    table, consider adding an index on the most restrictive columns in the
    predicate. Examine the columns in the indexes on this table and add them o
    the predicate if possible.

The Explain Information panel displays messages that are generated based on the results of the DB2 EXPLAIN command.

If the statement has an associated DECLARE CURSOR indicated by a number in the Declare Stmt column, the Explain data will be from the DECLARE CURSOR and not from the statement itself.