The EXPLAIN_OBJECT table identifies those data objects required by the
access plan generated to satisfy the SQL statement.
Table 124. EXPLAIN_OBJECT Table
| Column Name | Data Type | Nullable? | Key? | Description |
|---|---|---|---|---|
| EXPLAIN_REQUESTER | CHAR(8) | No | FK | Authorization ID of initiator of this Explain request. |
| EXPLAIN_TIME | TIMESTAMP | No | FK | Time of initiation for Explain request. |
| SOURCE_NAME | CHAR(8) | No | FK | Name of the package running when the dynamic statement was explained or name of the source file when the static SQL was explained. |
| SOURCE_SCHEMA | CHAR(8) | No | FK | Schema, or qualifier, of source of Explain request. |
| EXPLAIN_LEVEL | CHAR(1) | No | FK | Level of Explain information for which this row is relevant. |
| STMTNO | SMALLINT | No | FK | Statement number within package to which this explain information is related. |
| SECTNO | SMALLINT | No | FK | Section number within package to which this explain information is related. |
| OBJECT_SCHEMA | CHAR(8) | No | No | Schema to which this object belongs. |
| OBJECT_NAME | VARCHAR(18) | No | No | Name of the object. |
| OBJECT_TYPE | CHAR(2) | No | No | Descriptive label for the type of object. |
| CREATE_TIME | TIMESTAMP | Yes | No | Time of Object's creation; null if a table function. |
| STATISTICS_TIME | TIMESTAMP | Yes | No | Last time of update to statistics for this object; null if statistics do not exist for this object. |
| COLUMN_COUNT | SMALLINT | No | No | Number of columns in this object. |
| ROW_COUNT | INTEGER | No | No | Estimated number of rows in this object. |
| WIDTH | INTEGER | No | No | The average width of the object in bytes. Set to -1 for an index. |
| PAGES | INTEGER | No | No | Estimated number of pages that the object occupies in the buffer pool. Set to -1 for a table function. |
| DISTINCT | CHAR(1) | No | No | Indicates if the rows in the object are distinct (i.e. no
duplicates)
Possible values are:
|
| TABLESPACE_NAME | VARCHAR(18) | Yes | No | Name of the table space in which this object is stored; set to null if no table space is involved. |
| OVERHEAD | DOUBLE | No | No | Total estimated overhead, in milliseconds, for a single random I/O to the specified table space. Includes controller overhead, disk seek, and latency times. Set to -1 if no table space is involved. |
| TRANSFER_RATE | DOUBLE | No | No | Estimated time to read a data page, in milliseconds, from the specified table space. Set to -1 if no table space is involved. |
| PREFETCHSIZE | INTEGER | No | No | Number of data pages to be read when prefetch is performed. Set to -1 for a table function. |
| EXTENTSIZE | INTEGER | No | No | Size of extent, in data pages. This many pages are written to one container in the table space before switching to the next container. Set to -1 for a table function. |
| CLUSTER | DOUBLE | No | No | Degree of data clustering with the index. If >= 1, this is the CLUSTERRATIO. If >= 0 and < 1, this is the CLUSTERFACTOR. Set to -1 for a table, table function, or if this statistic is not available. |
| NLEAF | INTEGER | No | No | Number of leaf pages this index object's values occupy. Set to -1 for a table, table function, or if this statistic is not available. |
| NLEVELS | INTEGER | No | No | Number of index levels in this index object's tree. Set to -1 for a table, table function, or if this statistic is not available. |
| FULLKEYCARD | INTEGER | No | No | Number of distinct full key values contained in this index object. Set to -1 for a table, table function, or if this statistic is not available. |
| OVERFLOW | INTEGER | No | No | Total number of overflow records in the table. Set to -1 for an index, table function, or if this statistic is not available. |
Table 125. Possible OBJECT_TYPE Values
| Value | Description |
|---|---|
| IX | Index |
| TA | Table |
| TF | Table Function |