oracle官方文档--DBMS_SQLPA
DBMS_SQLPA
The DBMS_SQLPA package provides the interface SQL Performance Analyzer.
The chapter contains the following topics:
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Using DBMS_SQLPA
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Overview
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Security Model
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Summary of DBMS_SQLPA Subprograms
Using DBMS_SQLPA
-
Overview
-
Security Model
Overview
The DBMS_SQLPA package provides a capacity to help users predict the impact of system environment changes on the performance of a SQL workload. The interface lets users build and then compare two different versions of the workload performance, analyze the differences between the two versions, and unmask the SQL statements that might be impacted by the changes.
The package provides a task-oriented interface to implement the SQL Performance Analyzer. For example
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You use the CREATE_ANALYSIS_TASK Functions to create an analysis task for a single statement or a group of SQL statements.s
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The EXECUTE_ANALYSIS_TASK Function & Procedure executes a previously created analysis task.
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The REPORT_ANALYSIS_TASK Function displays the results of an analysis task.
Security Model
This package is available to PUBLIC and performs its own security checking. All analysis task interfaces (XXX_ANALYSIS_TASK) require privilege ADVISOR.
Summary of DBMS_SQLPA Subprograms
Table 124-1 DBMS_SQLPA Package Subprograms
| Subprogram | Description |
|---|---|
| CANCEL_ANALYSIS_TASK Procedure |
Cancels the currently executing task analysis of one or more SQL statements |
| CREATE_ANALYSIS_TASK Functions |
Creates an advisor task to process and analyze one or more SQL statements |
| DROP_ANALYSIS_TASK Procedure |
Drops a SQL analysis task |
| EXECUTE_ANALYSIS_TASK Function & Procedure |
Executes a previously created analysis task |
| INTERRUPT_ANALYSIS_TASK Procedure |
Interrupts the currently executing analysis task |
| REPORT_ANALYSIS_TASK Function |
Displays the results of an analysis task |
| RESET_ANALYSIS_TASK Procedure |
Resets the currently executing analysis task to its initial state |
| RESUME_ANALYSIS_TASK Procedure |
Resumes a previously interrupted analysis task that was created to process a SQL tuning set. |
| SET_ANALYSIS_TASK_PARAMETER Procedures |
Sets the SQL analysis task parameter value |
| SET_ANALYSIS_DEFAULT_PARAMETER Procedures |
Sets the SQL analysis task parameter default value |
CANCEL_ANALYSIS_TASK Procedure
This procedure cancels the currently executing analysis task. All intermediate result data is removed from the task.
Syntax
DBMS_SQLPA.CANCEL_ANALYSIS_TASK( task_name IN VARCHAR2);
Parameters
Table 124-2 CANCEL_ANALYSIS_TASK Procedure Parameters
| Parameter | Description |
|---|---|
| |
Name of the task to cancel |
Examples
Canceling a task when there is a need to stop it executing and it is not required to view any already-completed results:
EXEC DBMS_SQLPA.CANCEL_ANALYSIS_TASK(:my_task);
CREATE_ANALYSIS_TASK Functions
These functions create an advisor task to process and analyze one or more SQL statements. You can use different forms of this function to:
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Create an analysis task for a single statement given its text.
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Create an analysis task for a single statement from the cursor cache given its identifier.
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Create an analysis task for a single statement from the workload repository given a range of snapshot identifiers.
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Create an analysis task for a SQL tuning set.
In all cases, the function creates an advisor task and sets its parameters.
Syntax
SQL text format. This form of the function is called to prepare the analysis of a single statement given its text.
DBMS_SQLPA.CREATE_ANALYSIS_TASK( sql_text IN CLOB, bind_list IN sql_binds := NULL, parsing_schema IN VARCHAR2 := NULL, task_name IN VARCHAR2 := NULL, description IN VARCHAR2 := NULL) RETURN VARCHAR2;
SQL ID format. This form of the function is called to prepare the analysis of a single statement from the cursor cache given its identifier.
DBMS_SQLPA.CREATE_ANALYSIS_TASK( sql_id IN VARCHAR2, plan_hash_value IN NUMBER := NULL, task_name IN VARCHAR2 := NULL, description IN VARCHAR2 := NULL) RETURN VARCHAR2;
Workload Repository format. This form of the function is called to prepare the analysis of a single statement from the workload repository given a range of snapshot identifiers.
DBMS_SQLPA.CREATE_ANALYSIS_TASK( begin_snap IN NUMBER, end_snap IN NUMBER, sql_id IN VARCHAR2, plan_hash_value IN NUMBER := NULL, task_name IN VARCHAR2 := NULL, description IN VARCHAR2 := NULL) RETURN VARCHAR2;
SQLSET format. This form of the function is called to prepare the analysis of a SQL tuning set.
DBMS_SQLPA.CREATE_ANALYSIS_TASK( sqlset_name IN VARCHAR2, basic_filter IN VARCHAR2 := NULL, order_by IN VARCHAR2 := NULL, top_sql IN VARCHAR2 := NULL, task_name IN VARCHAR2 := NULL, description IN VARCHAR2 := NULL sqlset_owner IN VARCHAR2 := NULL) RETURN VARCHAR2;
Parameters
Table 124-3 CREATE_ANALYSIS_TASK Function Parameters
| Parameter | Description |
|---|---|
| |
Text of a SQL statement |
| |
A set of bind values |
| |
Name of the schema where the statement can be compiled |
| |
Optional analysis task name |
| |
Description of the SQL analysis task to a maximum of 256 characters |
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Identifier of a SQL statement |
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Hash value of the SQL execution plan |
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Begin snapshot identifier |
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End snapshot identifier |
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SQL tuning set name |
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SQL predicate to filter the SQL from the SQL tuning set |
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Order-by clause on the selected SQL |
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Top N SQL after filtering and ranking |
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The owner of the SQL tuning set, or |
Return Values
A SQL analysis task name that is unique by user (two different users can give the same name to their advisor tasks).
Examples
variable stmt_task VARCHAR2(64);
variable sts_task VARCHAR2(64);
-- Sql text format
EXEC :stmt_task := DBMS_SQLPA.CREATE_ANALYSIS_TASK(
sql_text => 'select quantity_sold from sales s, times t where s.time_id = t.time_id and s.time_id = TO_DATE(''24-NOV-00'')');
-- Sql id format (cursor cache)
EXEC :stmt_task := DBMS_SQLPA.CREATE_ANALYSIS_TASK(
sql_id => 'ay1m3ssvtrh24');
-- Workload repository format
exec :stmt_task := DBMS_SQLPA.CREATE_ANALYSIS_TASK(
begin_snap => 1,
end_snap => 2,
sql_id => 'ay1m3ssvtrh24');
-- Sql tuning set format (first we need to load an STS, then analyze it)
EXEC :sts_task := DBMS_SQLPA.CREATE_ANALYSIS_TASK( -
sqlset_name => 'my_workload', -
order_by => 'BUFFER_GETS', -
description => 'process workload ordered by buffer gets');
DROP_ANALYSIS_TASK Procedure
This procedure drops a SQL analysis task.The task and all its result data are deleted.
Syntax
DBMS_SQLPA.DROP_ANALYSIS_TASK( task_name IN VARCHAR2);
Parameters
Table 124-4 DROP_ANALYSIS_TASK Procedure Parameters
| Parameter | Description |
|---|---|
| |
The name of the analysis task to drop |
EXECUTE_ANALYSIS_TASK Function & Procedure
This function and procedure executes a previously created analysis task, the function version returning the new execution name.
Syntax
DBMS_SQLPA.EXECUTE_ANALYSIS_TASK( task_name IN VARCHAR2, execution_type IN VARCHAR2 := 'test execute', execution_name IN VARCHAR2 := NULL, execution_params IN dbms_advisor.argList := NULL, execution_desc IN VARCHAR2 := NULL) RETURN VARCHAR2;
DBMS_SQLPA.EXECUTE_ANALYSIS_TASK( task_name IN VARCHAR2, execution_type IN VARCHAR2 := 'test execute', execution_name IN VARCHAR2 := NULL, execution_params IN dbms_advisor.argList := NULL, execution_desc IN VARCHAR2 := NULL);
Parameters
Table 124-5 EXECUTE_ANALYSIS_TASK Function & Procedure Parameters
| Parameter | Description |
|---|---|
| |
Identifier of the task to execute |
| |
Type of the action to perform by the function. If
|
| |
A name to qualify and identify an execution. If not specified, it will be generated by the advisor and returned by function. |
| |
List of parameters (name, value) for the specified execution. The execution parameters have effect only on the execution for which they are specified. They will override the values for the parameters stored in the task (set via theSET_ANALYSIS_DEFAULT_PARAMETER Procedures). |
| |
A 256-length string describing the execution |
Usage Notes
SQL performance analyzer task can be executed multiples times without having to reset it. For example, when a task is created to perform a change impact analysis on a SQL workload, the created task has to be executed before making any change in the system environment to build a version of the workload that will be used as a reference for performance analysis. Once the change has been made, a second execution is required to build the post-change version of the workload. Finally, the task has to be executed a third time to let the advisor analyze and compare the performance of the workload in both versions.
Examples
1. Create a task with a purpose of change impact analysis
EXEC :tname := DBMS_SQLPA.CREATE_TUNING_TASK(
sqlset_name => 'my_sts');
2. Make baseline or the before change execution
EXEC DBMS_SQLPA.EXECUTE_TUNING_TASK(
task_name => :tname,
execution_type => 'test execute', execution_name => 'before_change');
3. Make change
...
4. Make the after change version of the workload performance
EXEC DBMS_SQLPA.EXECUTE_TUNING_TASK( task_name => :tname, - execution_type => 'test execute ', execution_name => 'after_change')
5. Compare the two versions of the workload
By default we always compare the results of the two last executions. The SQL Performance Analyzer uses the elapsed_time as a default metric for comparison. Here we are changing it to buffer_gets instead.
EXEC DBMS_SQLPA.SET_TUNING_TASK_PARAMETER( :tname,'comparison_metric', 'buffer_gets'); EXEC DBMS_SQLPA.EXECUTE_TUNING_TASK( task_name => :tname, - execution_type => 'test execute', - execution_name => 'after_change');
Use the following call if you would like to explicitly specify the two executions to compare as well as the comparison metric to use.
EXEC DBMS_SQLPA.EXECUTE_TUNING_TASK(
task_name => :tname, -
execution_type => 'compare performance',
execution_params => dbms_advisor.arglist(
'execution_name1',
'before_change',
'execution_name2',
'after_change',
'comparion_metric',
'buffer_gets'));
INTERRUPT_ANALYSIS_TASK Procedure
This procedure interrupts the currently executing analysis task. All intermediate result data will not be removed from the task.
Syntax
DBMS_SQLPA.INTERRUPT_ANALYSIS_TASK( task_name IN VARCHAR2);
Parameters
Table 124-6 INTERRUPT_ANALYSIS_TASK Procedure Parameters
| Parameter | Description |
|---|---|
| |
Identifier of the analysis task to interrupt |
Examples
EXEC DBMS_SQLPA.INTERRUPT_ANALYSIS_TASK(:my_task);
REPORT_ANALYSIS_TASK Function
This procedure displays the results of an analysis task.
Syntax
DBMS_SQLPA.REPORT_ANALYSIS_TASK( task_name IN VARCHAR2, type IN VARCHAR2 := 'text', level IN VARCHAR2 := 'typical', section IN VARCHAR2 := 'summary', object_id IN NUMBER := NULL, top_sql IN NUMBER := 100, task_owner IN VARCHAR2 := NULL, execution_name IN VARCHAR2 := NULL)) RETURN CLOB;
Parameters
Table 124-7 REPORT_ANALYSIS_TASK Function Parameters
| Parameter | Description |
|---|---|
| |
Name of the task to report |
| |
Type of the report to produce. Possible values are |
| |
Level of detail in the report:
|
| |
Optionally limit the report to a single section (
|
| |
Identifier of the advisor framework object that represents a given SQL in a tuning set (STS) |
| |
Number of SQL statements in a STS for which the report is generated |
| |
Owner of the relevant analysis task. Defaults to the current schema owner. |
| |
Name of the task execution to use. If |
Return Values
A CLOB containing the desired report.
Examples
-- Get the whole report for the single statement case. SELECT DBMS_SQLPA.REPORT_ANALYSIS_TASK(:stmt_task) from dual; -- Show me the summary for the sts case. SELECT DBMS_SQLPA.REPORT_ANALYSIS_TASK(:sts_task, 'TEXT', 'TYPICAL', 'SUMMARY') FROM DUAL; -- Show me the findings for the statement I'm interested in. SELECT DBMS_SQLPA.REPORT_ANALYSIS_TASK(:sts_task, 'TEXT', 'TYPICAL', 'FINDINGS', 5) from dual;
RESET_ANALYSIS_TASK Procedure
This procedure is called on an analysis task that is not currently executing to prepare it for re-execution. All intermediate result data will be deleted.
Syntax
DBMS_SQLPA.RESET_ANALYSIS_TASK( task_name IN VARCHAR2);
Parameters
Table 124-8 RESET_ANALYSIS_TASK Procedure Parameters
| Parameter | Description |
|---|---|
| |
Identifier of the analysis task to reset |
Examples
-- reset and re-execute a task EXEC DBMS_SQLPA.RESET_ANALYSIS_TASK(:sts_task); -- re-execute the task EXEC DBMS_SQLPA.EXECUTE_ANALYSIS_TASK(:sts_task);
RESUME_ANALYSIS_TASK Procedure
This procedure resumes a previously interrupted or FAILED (with a fatalerror) task execution.
Syntax
DBMS_SQLPA.RESUME_ANALYSIS_TASK( task_name IN VARCHAR2, basic_filter IN VARCHAR2 := NULL);
Parameters
Table 124-9 RESUME_ANALYSIS_TASK Procedure Parameters
| Parameter | Description |
|---|---|
| |
Identifier of the analysis task to resume |
| |
A SQL predicate to filter the SQL from the SQL tuning set. Note that this filter will be applied in conjunction with the basic filter (parameter |
Usage Notes
Resuming a single SQL analysis task (a task that was created to analyze a single SQL statement as compared to a SQL Tuning Set) is not supported.
Examples
-- Interrupt the task EXEC DBMS_SQLPA.INTERRUPT_ANALYSIS_TASK(:conc_task); -- Once a task is interrupted, we can elect to reset it, resume it, or check -- out its results and then decide. For this example we will just resume. EXEC DBMS_SQLPA.RESUME_ANALYSIS_TASK(:conc_task);
SET_ANALYSIS_TASK_PARAMETER Procedures
This procedure sets the SQL analysis task parameter value.
Syntax
This form of the procedure updates the value of a SQL analysis parameter of type VARCHAR2.
DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER( task_name IN VARCHAR2, parameter IN VARCHAR2, value IN VARCHAR2);
This form of the procedure updates the value of a SQL analysis parameter of type NUMBER.
DBMS_SQLPA.SET_ANALYSIS_TASK_PARAMETER( task_name IN VARCHAR2, parameter IN VARCHAR2, value IN NUMBER);
Parameters
Table 124-10 SET_ANALYSIS_TASK_PARAMETER Procedure Parameters
| Parameter | Description |
|---|---|
| |
Identifier of the task to execute |
| parameter |
Name of the parameter to set. The possible analysis parameters that can be set by this procedure are:
|
| |
New value of the specified parameter |
SET_ANALYSIS_DEFAULT_PARAMETER Procedures
This procedure sets the SQL analysis task parameter default value.
Syntax
This form of the procedure updates the default value of an analyzer parameter of type VARCHAR2.
DBMS_SQLPA.SET_ANALYSIS_DEFAULT_PARAMETER( parameter IN VARCHAR2, value IN VARCHAR2);
This form of the procedure updates the default value of an analyzer parameter of type NUMBER.
DBMS_SQLPA.SET_ANALYSIS_DEFAULT_PARAMETER( parameter IN VARCHAR2, value IN NUMBER);
Parameters
Table 124-11 SET_ANALYSIS_DEFAULT_PARAMETER Procedure Parameters
| Parameter | Description |
|---|---|
| |
Name of the parameter to set. The possible analysis parameters that can be set by this procedure are:
|
| |
New value of the specified parameter |