DBA_HIST_SQL_PLAN

DBA_HIST_SQL_PLAN displays the execution plan information for each child cursor in the workload repository. This view captures information from V$SQL_PLAN and is used with the DBA_HIST_SQLSTAT view. Column Datatype NULL Description DBID NUMBER NOT NULL Database ID SQL_ID VARCHAR2(13) NOT NULL SQL identifier of the parent cursor in the library cache PLAN_HASH_VALUE NUMBER NOT NULL Numerical representation of the SQL plan for the cursor. Comparing one PLAN_HASH_VALUE to another easily identifies whether or not two plans are the same (rather than comparing the two plans line by line). ID NUMBER NOT NULL A number assigned to each step in the execution plan OPERATION VARCHAR2(30) Name of the internal operation performed in this step (for example, TABLE ACCESS) OPTIONS VARCHAR2(30) A variation on the operation described in the OPERATION column (for example, FULL) OBJECT_NODE VARCHAR2(128) Name of the database link used to reference the object (a table name or view name). For local queries that use parallel execution, this column describes the order in which output from operations is consumed. OBJECT# NUMBER Object number of the table or the index OBJECT_OWNER VARCHAR2(30) Name of the user who owns the schema containing the table or index OBJECT_NAME VARCHAR2(31) Name of the table or index OBJECT_ALIAS VARCHAR2(65) Alias for the object OBJECT_TYPE VARCHAR2(20) Type of the object OPTIMIZER VARCHAR2(20) Current mode of the optimizer for the first row in the plan (statement line), for example, CHOOSE. When the operation is a database access (for example, TABLE ACCESS), this column indicates whether or not the object is analyzed. PARENT_ID NUMBER ID of the next execution step that operates on the output of the current step DEPTH NUMBER Depth (or level) of the operation in the tree. It is not necessary to issue a CONNECT BY statement to get the level information, which is generally used to indent the rows from the PLAN_TABLE table. The root operation (statement) is level 0. POSITION NUMBER Order of processing for all operations that have the same PARENT_ID SEARCH_COLUMNS NUMBER Number of index columns with start and stop keys (that is, the number of columns with matching predicates) COST NUMBER Cost of the operation as estimated by the optimizer's cost-based approach. For statements that use the rule-based approach, this column is null. CARDINALITY NUMBER Estimate, by the cost-based optimizer, of the number of rows produced by the operation BYTES NUMBER Estimate, by the cost-based optimizer, of the number of bytes produced by the operation OTHER_TAG VARCHAR2(35) Describes the contents of the OTHER column. See EXPLAIN PLAN for values. PARTITION_START VARCHAR2(5) Start partition of a range of accessed partitions PARTITION_STOP VARCHAR2(5) Stop partition of a range of accessed partitions PARTITION_ID NUMBER Step that computes the pair of values of the PARTITION_START and PARTITION_STOP columns OTHER VARCHAR2(4000) Other information specific to the execution step that users may find useful. See EXPLAIN PLAN for values. DISTRIBUTION VARCHAR2(20) Stores the method used to distribute rows from producer query servers to consumer query servers CPU_COST NUMBER CPU cost of the operation as estimated by the optimizer's cost-based approach. For statements that use the rule-based approach, this column is null. IO_COST NUMBER I/O cost of the operation as estimated by the optimizer's cost-based approach. For statements that use the rule-based approach, this column is null. TEMP_SPACE NUMBER Temporary space usage of the operation (sort or hash-join) as estimated by the optimizer's cost-based approach. For statements that use the rule-based approach, this column is null. ACCESS_PREDICATES VARCHAR2(4000) Predicates used to locate rows in an access structure. For example, start or stop predicates for an index range scan. FILTER_PREDICATES VARCHAR2(4000) Predicates used to filter rows before producing them PROJECTION VARCHAR2(4000) Expressions produced by the operation TIME NUMBER Elapsed time (in seconds) of the operation as estimated by the optimizer's cost-based approach. For statements that use the rule-based approach, this column is null. QBLOCK_NAME VARCHAR2(31) Name of the query block REMARKS VARCHAR2(4000) Remarks TIMESTAMP DATE Timestamp for when the plan was produced OTHER_XML CLOB Provides extra information specific to an execution step of the execution plan. The content of this column is structured using XML because it allows multiple pieces of information to be stored, including the following: Name of the schema against which the query was parsed Release number of the Oracle Database that produced the explain plan Hash value associated with the execution plan Name (if any) of the outline or the SQL profile used to build the execution plan Indication of whether or not dynamic sampling was used to produce the plan The outline data, a set of optimizer hints that can be used to regenerate the same plan