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SQL Optimizer for Oracle 10.0 - User Guide

Welcome to SQL Optimizer
About SQL Optimizer SQL Optimization Workflow New in This Release Additional Resources Database Privileges Database Privileges Script Connect to the Database Windows Layout Customize Toolbars Keyboard Shortcuts Support Bundle Register SQL Optimizer Check for Updates SQL Operations
ALL PARTITION ALTER INDEX AND EQUAL ANTI JOIN BITMAP AND BITMAP COMPACTION BITMAP CONSTRUCTION BITMAP CONVERSION BITMAP INDEX BITMAP JOIN INDEX UPDATE BITMAP JOIN INDEX UPDATE STATEMENT BITMAP KEY ITERATION BITMAP MERGE BITMAP MINUS BITMAP OR BUFFER SORT CARTESIAN JOIN COLLECTION ITERATOR CONCATENATION CONNECT BY CONNECT BY PUMP COUNT COUNT STOPKEY CREATE AS SELECT CUBE SCAN DDL STATEMENT DELETE DOMAIN INDEX FAST FULL INDEX SCAN FILTER FIRST ROWS FIXED INDEX FIXED TABLE FOR UPDATE FULL INDEX SCAN FULL INDEX SCAN DESCENDING FULL INDEX SCAN (MIN/MAX) HASH GROUP BY HASH GROUP BY PIVOT HASH JOIN HASH JOIN BUFFERED HASH PARTITION HASH UNIQUE INDEX INDEX BUILD NON UNIQUE INDEX RANGE SCAN INDEX RANGE SCAN DESCENDING INDEX RANGE SCAN (MIN/MAX) INDEX SAMPLE FAST FULL SCAN INDEX SKIP SCAN INDEX SKIP SCAN DESCENDING INDEX UNIQUE SCAN INLIST ITERATOR INLIST PARTITION INSERT INTERSECTION INTO INVALID PARTITION ITERATOR PARTITION LOAD AS SELECT MAT_VIEW ACCESS MAT_VIEW REWRITE ACCESS MERGE JOIN MINUS MULTI-TABLE INSERT NESTED LOOPS OUTER JOIN PARTITION PARTITION HASH EMPTY PARTITION LIST PARTITION RANGE PROJECTION PX BLOCK ITERATOR PX COORDINATOR PX ITERATOR PX PARTITION PX PARTITION HASH ALL PX PARTITION LIST ALL PX PARTITION RANGE ALL PX RECEIVE PX SEND RANGE PARTITION RECURSIVE EXECUTION RECURSIVE WITH PUMP REFERENCE MODEL REMOTE SELECT SEMI JOIN SEQUENCE SINGLE PARTITION SINGLE RANGE PARTITION SORT SORT AGGREGATE SORT GROUP BY SORT GROUP BY CUBE SORT GROUP BY NOSORT SORT GROUP BY ROLLUP SORT JOIN SORT ORDER BY SORT UNIQUE SQL MODEL TABLE ACCESS TABLE ACCESS BY GLOBAL INDEX ROWID TABLE ACCESS BY INDEX ROWID TABLE ACCESS BY LOCAL INDEX ROWID TABLE ACCESS BY ROWID TABLE ACCESS BY USER ROWID TABLE ACCESS CLUSTER TABLE ACCESS FULL TABLE ACCESS HASH TABLE ACCESS SAMPLE TABLE QUEUE TEMP TABLE GENERATION TEMP TABLE TRANSFORMATION UNION UNION ALL UNION ALL (RECURSIVE WITH) UNPIVOT UPDATE VIEW VIEW PUSHED PREDICATE WINDOW
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Review Execution Plans

SQL Optimizer provides a variety of formats for displaying an execution plan. After selecting a plan format, you can customize the plan display and the Execution Plan window.

To select a plan format

  1. Select a SQL statement.

  2. Right-click the execution plan and select View Plan | option.

  3. Select one of the following formats:

    • Tree Plan
    • DBMS_XPlan (Formatted)
    • DBMS_XPlan (Plain Text)
    • Graphic Plan
    • MS Graphic Plan
    • Plain Language Plan
  4. For more information about each format, review the following sections.

Plan Formats

To use the Tree Plan

  1. Right-click an execution plan and select View Plan | As Tree Plan.

    ClosedView Tree Plan
  2. Review the steps. The first line of the execution plan displays the SQL statement type, such as SELECT. The remaining lines represent an operation. The steps are numbered in the order of execution to make the plan easier to read.

  3. Select a layout style for the tree plan from the Execution Plan toolbar (right panel). Each style displays different plan details (operators, predicates, statistics).

  4. To select which items/columns to display in the execution plan, right-click the plan and select Plan Options. The settings will apply to the current module only.

    • Select the items to include (such as cost, disk reads/writes).
    • Select which items to display as columns.
  5. To get additional Help on a step, select the step. Then right-click and select Help on plan step.

  6. In the Actual Plan tab, to display a comparison of Oracle estimates and actual statistics, click the Plan Comparison button in the Execution Plan toolbar.

  7. To animate the steps, right-click the plan and select Animate Plan Steps.

To use DBMS_XPlan

  1. Right-click an execution plan and select View Plan | As DBMS_XPlan (Formatted) or DBMS_XPlan (Plain Text).
  2. The plan displays using DBMS_XPLAN.

  3. To select a display level for DBMS_XPlan (Formatted), click the arrow beside the Switch DBMS_XPlan level button and select an option.

To use the Plain Language Plan

  1. Right-click an execution plan and select View Plan | As Plain Language Plan.

    ClosedView Plain Language Plan

To use Graphic Plan

  1. Right-click an execution plan and select View Plan | As Graphic Plan.

    ClosedView Graphic Plan
  2. Hover over a step to display step details in a tooltip.
  3. To animate the steps, right-click the plan and select Animate Plan Steps.
  4. Right-click the plan and select Step Description to display the step description in plain language in the footer.
  5. To copy the plan as an image, right-click the plan and select Copy.

To use MS Graphic Plan

  1. Right-click an execution plan and select View Plan | As MS Graphic Plan.

    ClosedView MS Graphic Plan
  2. The available options are the same as the Graphic Plan.

To return to previous view

  • To return to your previous view, click the Switch View Plan button at the bottom of the Execution Plan toolbar. Use this button to easily toggle between two views. Click the arrow to select a different view.

Customize Tree Plan

To customize font style and color

  1. Go to Options | General | Execution Plan.
  2. You can customize text color and font style for each item in a plan. Settings apply to all Execution Plan panes. See Execution Plan Options for more information.
    • You can also specify warning thresholds for applying highlighting.

Customize Execution Plan Window

To display step description in footer

  • Right-click the plan and select Step Description. A description of the selected step displays in the footer of the Execution Plan pane. This is helpful when using one of the graphic displays.

To display additional plan information

  • Right-click the plan and select Plan Information to display additional information if the plan uses any of the following: cardinality feedback, dynamic sampling, SQL plan directives, or adaptive plan.

 

Related Topics

About Execution Plans

Retrieve Execution Plans

Animate Execution Plans

Copy Execution Plans

Animate Execution Plans

You can animate each step in the execution plan in the order SQL Optimizer executes them.

To animate the execution plan or cancel the animation

» Right-click the execution plan and select Animate Plan Steps.

 

Related Topics

About Execution Plans

Retrieve Execution Plans

Review Execution Plans

Fill Missing Execution Plans

Copy Execution Plans

You can copy an execution plan from the Execution Plan pane and paste it into another file as text or a bitmap image.

To copy an execution plan

  1. In an Execution Plan pane, right-click the execution plan and select Copy.
  2. You can then paste the plan using another application such as Microsoft Word or Notepad.
    • Tree Plan, DBMS_XPLAN, and Plain Language Plan views can be pasted as text or in bitmap format. Applications such as Microsoft Word allow you to choose the format using the Paste Special option.
    • You can use text applications such as Notepad to paste execution plans in text format.
    • You can use graphic applications such as Microsoft Paint to paste execution plans in bitmap format.

 

 

Related Topics

About Execution Plans

Retrieve Execution Plans

Review Execution Plans

Fill Missing Execution Plans

Flush Shared Pool

You can remove all saved SQL statements from Oracle's SGA by flushing the shared pool before using Inspect SGA to collect SQL. Flushing the shared pool before starting a job collecting currently running SQL can be useful because SQL statistics retrieved are for SQL collected during the specified monitoring time.

Caution: Flushing the shared pool can impact the performance of your production server while the server repopulates its memory buffers.

To flush the shared pool

  1. Select the Inspect SGA tab in the main window.
  2. Click beside the Group list and select a group.

  3. Right-click a job in the Job List pane and select Flush Shared Pool.

    Notes:

    • You need to have the privileges to execute the ALTER SYSTEM command to flush the shared pool.

    • Flushing the shared pool before starting a job collecting executed SQL from the SQL area can decrease the number of statements collected.

  

Related Topics  

About Inspect SGA

Use Inspect SGA

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