The EXPLAIN_OPERATOR table contains all the operators needed to satisfy the SQL statement by the SQL compiler.
For the definition of this table, see EXPLAIN_OPERATOR Table Definition.
Table 101. EXPLAIN_OPERATOR 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. |
| OPERATOR_ID | SMALLINT | No | No | Unique ID for this operator within this query. |
| OPERATOR_TYPE | CHAR(6) | No | No | Descriptive label for the type of operator. |
| TOTAL_COST | DOUBLE | No | No | Estimated cumulative total cost (in instructions) of executing the chosen access plan up to and including this operator. |
| IO_COST | DOUBLE | No | No | Estimated cumulative I/O cost (in data page I/Os) of executing the chosen access plan up to and including this operator. |
| CPU_COST | DOUBLE | No | No | Estimated cumulative CPU cost (in instructions) of executing the chosen access plan up to and including this operator. |
| FIRST_ROW_COST | DOUBLE | No | No | Estimated cumulative cost (in timerons) of fetching the first row for the access plan up to and including this operator. This value includes any initial overhead required. |
| RE_TOTAL_COST | DOUBLE | No | No | Estimated cumulative cost (in timerons) of fetching the next row for the chosen access plan up to and including this operator. |
| RE_IO_COST | DOUBLE | No | No | Estimated cumulative I/O cost (in data page I/Os) of fetching the next row for the chosen access plan up to and including this operator. |
| RE_CPU_COST | DOUBLE | No | No | Estimated cumulative CPU cost (in timerons) of fetching the next row for the chosen access plan up to and including this operator. |
| COMM_COST | DOUBLE | No | No | Estimated cumulative communication cost (in TCP/IP frames) of executing the chosen access plan up to and including this operator. |
| FIRST_COMM_COST | DOUBLE | No | No | Estimated cumulative communications cost (in TCP/IP frames) of fetching the first row for the chosen access plan up to and including this operator. This value includes any initial overhead required. |
| NODES_USED | CLOB(64K) | Yes | No | Cumulative list of nodes involved in executing the chosen access plan up to and including this operator. |
Table 102. OPERATOR_TYPE Values
| Value | Description |
|---|---|
| DELETE | Delete |
| FETCH | Fetch |
| FILTER | Filter rows |
| GENROW | Generate Row |
| GRPBY | Group By |
| HSJOIN | Hash Join |
| INSERT | Insert |
| IXAND | Dynamic Bitmap Index ANDing |
| IXSCAN | Index Scan |
| MSJOIN | Merge Scan Join |
| NLJOIN | Nested loop Join |
| RETURN | Result |
| RIDSCN | Row Identifier (RID) Scan |
| SORT | Sort |
| TBSCAN | Table Scan |
| TEMP | Temporary Table Construction |
| TQ | Table Queue |
| UNION | Union |
| UNIQUE | Duplicate Elimination |
| UPDATE | Update |