Key Data

If an index is used and LEVEL(INDEXES) is not specified, information about the key columns is presented. The data is derived from the SYSIBM.SYSKEYS and SYSIBM.SYSCOLUMNS tables.

If a matching index scan is used in the access path, the report indicates the columns that are used in the index scan. This is indicated by an arrow (<===) in the column named KEY USED. The number of arrows corresponds to the contents of the matching columns field MATCHCOLS in the PLAN_TABLE report block.

For details on how to specify EXPLAIN commands refer to the Report Command Reference.

Explain Report - Key Data Block

Here is an example of the explain key data block section.

KEY                                      KEY                               KEY
NO. COLUMN NAME       COL.TYPE LNG NULL  CARD. ORDER LOW2KEY    HIGH2KEY   USED
                      COL.STAT LENGTH2   TYPESCHEMA  TYPENAME
                                                     CREATED
--- ----------------- -------- --- ----  ----- ----- ---------- ---------- ----
  1 LOCATION          VARCHAR  128 NO        1 ASC.  X'40404040 X'40404040 <===
                                      0  SYSIBM      VARCHAR
                                                     0001-01-01-00.00.00.000000
  2 COLLID            VARCHAR  128 NO       87 ASC.  X'4144424C X'55545255
                                      0  SYSIBM      VARCHAR
                                                     0001-01-01-00.00.00.000000
  3 NAME              VARCHAR  128 NO      576 ASC.  X'41444232 X'535F5550
                                      0  SYSIBM      VARCHAR
                                                     0001-01-01-00.00.00.000000
  4 VERSION           VARCHAR  122 NO       55 ASC.  X'31404040 X'56385231
                                      0  SYSIBM      VARCHAR
                                                     0001-01-01-00.00.00.000000