Labels:text | screenshot | number | font | black and white | parallel | document OCR: Column Description Statement_ID The Statement_ID you set in the EXPLAIN PLAN command; it "names" the query for future reference. Timestamp A timestamp recording when the EXPLAIN PLAN command was issued. Remarks A remark column; you can add remarks to existing records in PLAN TABLE via the UPDATE command. Operation The SQL operation performed in the step. Options The option used for the operation, such as UNIQUE SCAN or RANGE SCAN for the INDEX operation. Object_Node The database link used to refer to an object, or, in the Parallel Query Option, the query server process used by the operation. Object_Owner The owner of the object referenced by the operation. Object_Name The name of the object referenced by the operation. Object_Instance The ordinal position of the object, as it exists in the SQL being explained. Object_Type An attribute of the object, such as UNIQUE for indexes. Optimizer The optimizer mode used (such as FIRST_ROWS or RULE). Search Columns Not currently used. ID A number assigned to each step in the explain plan; with Parent_ID, establishes the hierarchy of steps in the execution path. Parent_ID The ID of the step that is the "parent" of the current step in the hierarchy of the execution path Position The order of processing for steps that have the same Parent_ID. In the first row generated for an explain plan, this column contains the optimizer's estimation of the statement's "cost" (if cost-based optimization is used; otherwise, no cost is calculated). Cost Relative cost for the step, if cost-based optimization is used; only available in Oracle7.3. Cardinality Only available in Oracle7.3; the expected number of rows returned from the operation. Bytes Only available in Oracle7.3; the "width" of each returned row. Other Tag Only available in Oracle7.3; if the value is SERIAL FROM_REMOTE, the SQL in the Other column will be executed on the remote node. The other values for Other_Tag describe the operation's usage within the Parallel Query option. Other For distributed queries, Other contains the text of the SQL that is executed on the remote node. Figure 2: Column descriptions for PLAN_TABLE.
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