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SQLSC_METRICS (SCM)

The SQLSC_METRICS (SCM) table consists of one row for each processing step for each query. Metrics are kept for the original query, and each optimized query.

Processing steps include the following processes (these steps appear for each SELECT block, except UNION and ORDER BY, which can only be specified once per query):

Column Name

SQL Data Type

Nullable

Description

SCM_SCV_ID

CHAR(16)

No

References SQLSC_VERSION

SCM_TABLE_NAME

CHAR(48)

No

authId.tableName correlationName

SCM_STEP

INTEGER

No

Processing step number, a number that reflects the order in which processing occurs

SCM_PROCESS

CHAR(24)

No

Text description of step

SCM_SUBSEL_NO

SMALLINT

No

Subselect number

SCM_SUBQRY_NO

SMALLINT

No

Subquery number within a subselect

SCM_TBL_NO

SMALLINT

No

position in table expression tree relative to zero (see note following table)

SCM_DBID

SMALLINT

No

Database ID of table (see note following table)

SCM_TBL_NM

CHAR(3)

No

3-character table name (see note following table)

SCM_KEY

CHAR(5)

No

5-character key name (see note following table)

SCM_SETS_AVG

INTEGER

No

Times executed

SCM_SCANKY_AVG

INTEGER

No

Number of Index entries scanned (see note following table)

SCM_SCANDT_AVG

INTEGER

No

Number of rows accessed in the data area (see note following table)

SCM_ROWS_AVG

INTEGER

No

Rows accepted (after filtering with predicates not evaluated by Compound Boolean Selection (CBS))

Note: These fields are blank or zero except for table-level processes 1 – 3.