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(128)

Name of the user who owns the schema containing the table or index

OBJECT_NAME

VARCHAR2(128)

Name of the table or index

OBJECT_ALIAS

VARCHAR2(261)

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, ALL_ROWS. 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(64)

Start partition of a range of accessed partitions

PARTITION_STOP

VARCHAR2(64)

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(128)

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 statistics were used to produce the plan

• The outline data, a set of optimizer hints that can be used to regenerate the same plan

CON_DBID

NUMBER

The database ID of the PDB for the sampled session

CON_ID

NUMBER

The ID of the container that CON_DBID identifies. Possible values include:

• 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

• 1: This value is used for rows containing data that pertain to only the root

• n: Where n is the applicable container ID for the rows containing data