Oracle baseline fixed. This is not accurate.
Oracle baseline fixed. var v_num number; Apr 10, 2025 · In this case, fixed SQL Plan baseline hints overrides the sql profile hints but optimizer also attempted to apply as many hints as possible from the SQL Profile. The baseline is implemented as a If fixed plans exist in the plan baseline, then the optimizer uses the fixed plan with the lowest cost. 1. FIXED=YES tells the optimizer to choose a fixed SQL plan baseline in preference to FIXED=NO. Oracle ver 11. Test code is as follows. The DBMS_SPM package supports the SQL plan management feature by providing an interface for the DBA or other user to perform controlled manipulation of plan history and SQL plan baselines maintained for various SQL statements. When an SQL statement is executed, the Oracle optimizer determines the optimal execution plan for that statement based on various factors such as statistics, system settings, and bind variables. Use the DBMS_SPM package to define a staging table, which is then used to pack and unpack SQL plan baselines. Nov 8, 2024 · The SIGNATURE column of DBA_SQL_PLAN_BASELINES is not being populated. When we “fix” a plan, (we mark it as fixed), we tell the optimizer we want this plan to be used, no other plans. DROP_SQL_PLAN_BASELINE( sql_handle => 'SQL_164b2be280f1ffba'); dbms_output. SQL plan baselines preserve performance of SQL statements, regardless of changes in the database. Dec 4, 2020 · The details for the plan baselines can be found like this: SELECT sql_handle,plan_name,origin,enabled,accepted,fixed FROM dba_sql_plan_baselines WHERE plan_name ='SQL_PLAN_7zwc0njc3y9bx2c993bf4'; Result: After fixing the plan, all the plan alternatives for the SQL ID can be seen below: SELECT TO_CHAR(LAST_ACTIVE_TIME, 'dd. SELECT * FROM dba_sql_plan_baselines Consider a baseline for the plan with the lowest cost or best elapsed time. DISPLAY_CURSOR or Learn how to create a SQL Plan Baseline in Oracle step-by-step. Before generating the SQL Plan Baseline, it is highly recommended that you optimize all or the most critical SQL statements that are selected to be transported to target database. Oct 23, 2009 · My interpretation is: If you are allowing your baselines to evolve, but you have a plan that you are 100% sure is the only one you want, and you do not want Oracle to try to improve on it - mark it 'fixed'. Use the DBMS_SPM package to define a staging table, DBMS_SPM. Mar 1, 2009 · With baseline use enabled, when the optimizer reparses a SQL statement, it examines the plans stored in the baseline for that SQL statement and chooses the best among them. mm. load_plans_from_cursor_cache( sql_id => '&sql_id'); END; / Suppose you have multiple plan hash value of the sql_id and you wish to create baseline with a particular plan hash value , […] Feb 13, 2018 · So I generate the good plan using index hint and then created the baseline with the plans and connect the wanted plan to the query sql_id, and change the fixed attribute to 'YES'. Nov 29, 2022 · If you want to delete sql_plan_baseline, it's done with sql_handle and plan_name. and later: How to Accept & Unaccept Plans in SQL Plan Baselines May 29, 2023 · What is sql baseline? SQL Plan Baselines in Oracle Database are a way to maintain the performance stability of SQL statements. I executed the DBMS_XPLAN. 1 and later: FIXED Plans of SQL Plan Baselines This article will show you how to manage SQL plan baselines—including capturing, selecting, and evolving baselines—by using Oracle Enterprise Manager and SQL from the command line to ensure the optimal performance of SQL statements. Now, delete the plan you've fixed and get ready for fixing with SQLPatch. CREATE TABLE TAB_AASSELECT * FROM DBA_USERS; CREATE TABLE TAB_BASSELECT T. Before creating a fixed baseline, carefully consider the time period you choose as a baseline, because the baseline should represent the system operating at an optimal level. SQL Plan Management in Oracle Most important point in the Performance Tuning is that maintain the SQL performance in spite of the changes. In a SQL*Plus session run the non-hinted SQL statement so we can begin the SQL plan baseline SQL plan baselines preserve performance of SQL statements, regardless of changes in the database. PACK_STGTAB_BASELINE to copy the baselines into a staging table, and Oracle Data Pump to transfer the table to another database. First check that the values of the following parameters in the May 8, 2020 · I'm frequently asked about the difference between SQL profiles and SQL plan baselines and why SQL profiles can be shared but SQL plan baselines can't. Mar 11, 2019 · Oracle SQL Plan Management (SPM) is a feature in Oracle Database that captures all the historical execution plans for a query. . put_line(drop_result); end; / baseline HOW TO PERFORMANCE All aspects of managing and monitoring SQL plan baselines can be done through Oracle Enterprise Manager or the PL/SQL packages DBMS_SPM, DBMS_XPLAN and the DBA view DBA_SQL_PLAN_BASELINES. Sep 28, 2017 · A fixed plan in the SQL Plan Baseline, is a plan that is preferred by the optimizer. In any case, here is the issue that we are trying to fix with SQL Plan Baselines. This enhancement simplifies baseline creation by specifying exact time periods rather than looking up snapshot numbers. Basically, with SQL plan baseline, you can change the execution plan of a sql […] Aug 30, 2019 · I also tried to mark the baseline as fixed, but it was useless. We have a query that i An sql_handle can have multiple sql baselines tagged, So if you want to drop all the sql baselines of that handle, then drop the sql handle itself. 0, the parameter optimizer_capture_sql_plan_baselines is set to false and optimizer_use_sql_plan_baselines is set to true What am I doing wrong? Thanks in advance. The baseline is implemented as a Jun 13, 2024 · FIXED=YES tells the optimizer to choose a fixed SQL plan baseline in preference to FIXED=NO. Jun 13, 2024 · FIXED=YES tells the optimizer to choose a fixed SQL plan baseline in preference to FIXED=NO. It is based upon the data collected with the following article: Nov 29, 2019 · Hi, I will explain SQL Plan Management Using SQL Plan Baselines in this article. Optionally, fix the execution plan of a baseline to prevent the database from using an alternative SQL plan baseline. For some time I’ve been puzzled by this question because the database doesn't automatically re-enable SQL plan baselines once they've been disabled. Jan 10, 2012 · Updated this other thread but then moderators locked it. If no fixed plans exist in the plan baseline, then the optimizer uses the baseline plan with the lowest cost. Nov 2, 2020 · A SQL Plan baseline is a Oracle feature introduced with Oracle DB 11g. SQL plan management uses a mechanism called a SQL plan baseline, which is a set of accepted plans that the optimizer is allowed to use for a SQL statement. However, the internal mechanism to enforce a particular execution plan is the same whether the plan baseline is fixed or not. In the future, you can compare the baseline with other baselines or snapshots captured during periods of poor performance to analyze performance degradation over time. We would like to show you a description here but the site won’t allow us. It is commonly Creating a Baseline By default, Oracle AI Database automatically maintains a system-defined moving window baseline. About Managing SQL Plan Baselines This topic describes the available interfaces and basic tasks for SQL plan management. If a fixed plan is reproducible using the hints stored in plan baseline, then the optimizer always chooses the lowest-cost fixed plan baseline over plan baselines that are not fixed. Nov 8, 2024 · The core idea presented by this note is to continue gathering CBO statistics for application schemas as usual, but create a clean baseline for non-application objects (data dictionary, fixed objects and system performance). If a fixed plan exists in a baseline, the optimizer will give priority to that fixed plan, even if a better, lower cost plan is available. Nevertheless, it Jun 27, 2024 · A SQL plan baseline with FIXED=YES and ENABLED=NO is not considered a fixed plan. New plans will be captured in the SQL plan history even if a statement’s existing (non-fixed) SQL plan baselines have ENABLED=NO. Apr 14, 2022 · Leave a reply Enable and Disable the SQL PLAN Baseline in Oracle Check the SQL Plan Baseline in Oracle SELECT sql_handle, plan_name, enabled, accepted FROM dba_sql_plan_baselines Enable the SQL ID plan in SQL Plan Baseline in Oracle: Note: SQL_HANDLE_VALUE or PLAN_NAME_VALUE taken from first query. This is where the most important benefit of baselines comes in. This chapter explains the concepts and tasks relating to SQL plan management using the DBMS_SPM package. SQL Profile creation Database upgrade and using new Optimizer Stale statistics When enabled, the optimizer looks for a SQL plan baseline for the SQL statement being compiled. Mar 19, 2025 · Step 3: Create a SQL Plan Baseline (If Not Already Exists) If no baseline exists, create one manually: Accessing the SQL Plan Baseline Page in Cloud Control The SQL Plan Control page in Cloud Control is a GUI that shows information about SQL profiles, SQL patches, and SQL plan baselines. Steps : 1. Complete the following steps: Select a SQL plan baseline that is not fixed. 2 on AIX. This would enable a DBA to essentially guarantee (or at least make most likely) a very specific plan to be used by If you have the sql_id of the sql query, then you can create a baseline of that using below code. With that, you can create a baseline for the good plan from the execution plans available in SPM and enable that baseline to ensure that the system picks only the good plan from the baseline. In this context, a plan includes all plan-related information (for example, SQL plan identifier, set of hints, bind values, and optimizer environment) that the optimizer needs to reproduce an execution plan. Jun 10, 2021 · Hi Chris/Connor. The baseline is implemented as a Aug 21, 2025 · This Document provides guidance on how to diagnose issues where a SQL Plan Management (SPM) Baseline is not Used. May 1, 2023 · It relies on Oracle Database 19c (hint usage reporting) and a hidden parameter to force the SQL statement to use the outline in the SQL plan baseline even if the resulting plan doesn't match the SQL plan baseline (a pretend match). Jan 1, 2020 · Be aware that if a SQL plan baseline is fixed for a particular query, but other non-accepted plans in the SQL plan history were previously captured (for this query) then these plan history entries will be subject to evolution. The use of SQL plan baselines is controlled by the OPTIMIZER_USE_SQL_PLAN_BASELINES parameter, which is set to TRUE by default. Is this bahaviour due to binds , if yes how to solve my problem , pls help . Enabled: Select this check box to indicate that the loaded plans are enabled plans. * FROM DBA_OBJECTS T, (SE Mar 19, 2014 · Hello, sql query is not using accepted fixed and enabled baseline optimizer_use_sql_plan_baselines boolean TRUE Nov 3, 2020 · How SQL plan baseline plans are managed in the long term, accounting for how SQL execution plans may need to change. 991149 . So I thought it would be a good idea to write a post explaining the differences between them and how they interact. Capture The capture function of SQL plan management captures the various optimizer plans used by SQL statements. The baseline is implemented as a May 23, 2021 · SQL plan baseline is one of the most used tuning technique in Oracle database. Access to the DBMS_SPM package requires the ADMINISTER SQL MANAGEMENT OBJECT privilege. If fixed plans exist in the plan baseline, then the optimizer uses the fixed plan with the lowest cost. yyyy hh24:mi Sep 29, 2025 · Oracle 11g introduced the ability to create baselines using date and time values instead of snapshot IDs. Aug 4, 2010 · Fixing SQL Plan Baselines Another option that can be used with SQL Plan Baselines is to mark one (or more) specific plan as a fixed baseline. SQL plan management adapts to such changes by verifying and accepting only plan changes that improve performance. the Oracle version is 11. While the Oracle Optimizer is perfectly suited to evaluate the best possible plan without any user intervention, a SQL statement’s execution plan can change unexpectedly for a variety of reasons including re-gathering optimizer statistics, changes to the optimizer parameters or schema Oct 24, 2025 · A fixed plan is an accepted plan that is marked as preferred, so that the optimizer considers only the fixed plans in the baseline. However, you may want to manually create a fixed baseline that represents the system operating at an optimal level, so you can compare it with other baselines or snapshots captured during periods of poor performance. 1 and later: How to Create A SQL Plan Baseline From A Historical Execution Plan In The Automatic Workload Repos Dec 17, 2012 · My query has 6 bind variables . It influences the query optimizer and forces the optimizer to create specific execution plans for a given SQL statement. Only that it prefers a fixed plan to a non-fixed one. Jan 12, 2024 · You can check the current value using the DBA_SQL_PLAN_BASELINES view using the FIXED column. We have a SQL to get the SQL_HANDLE and PLAN_NAME from the SQL_ID but relies on the SIGNATURE column being populated. Jan 26, 2017 · 4 To enable baseline usage, optimizer_use_sql_plan_baselines must be true. The table is refreshed to show the SQL execution plan with the value YES in the Fixed column of the table. We have a production 12c Database (12. Click Go. Oct 20, 2025 · Oracle Database - Enterprise Edition - Version 11. DISPLAY_SQL_PLAN_BASELINE function and the output shows that the wanted plan marked as fixed=yes. Learn how to fix poorly performing SQL after a database upgrade by utilizing SQL Plan Baselines: practical steps to identify and resolve regression issues. Nigel Bayliss, optimizer PM, has this to say about fixed plans in his SPM cheat sheet: I often see FIXED=YES proposed in cases where the SQL plan baseline isn’t being used because the optimizer is not using the plan encoded in the plan baseline. May 17, 2016 · Sometime DBAs need to create SQL Baseline for particular SQL_ID for plan stabilization 1) VERIFY CURRENTLY EXISTING SQL PLAN BASELINES select * from dba_sql May 16, 2021 · Hello All, I want two different queries to use the same plan in Oracle 19c. Why is that?”. Aug 27, 2025 · Oracle Database - Enterprise Edition - Version 11. declare drop_result pls_integer; begin drop_result := DBMS_SPM. There are lots of changes and factors that influence the Optimizer and execution plan as follows. Jun 19, 2024 · This is not accurate. If there is a better plan, fixing may be required for the query to work with the correct query plan. Feb 9, 2025 · Oracle Database supports the export and import of SQL plan baselines using its import and export utilities or Oracle Data Pump. The optimizer will choose the lowest cost accepted plan but will give preference to a fixed plan. In other words, plan fix can be done. DECLARE l_plans_loaded PLS_INTEGER; BEGIN l_plans_loaded := DBMS_SPM. DISPLAY_CURSOR or Apr 8, 2024 · Hello All, When we try to create a baseline for one of the Fixed Price Projects, we get this error The message is invokeBudgetGenerationJBO-FND:::FND_GENERIC_MESSAGE: Jul 26, 2019 · In some cases in Oracle databases, the optimizer may make the wrong decision and cause this query to run with the wrong query plan. Improve query performance, prevent plan regressions, and manage execution plans safely with DBA-friendly scripts and tips. Baseline is ENABLED and FIXED, and REPRODUCED column reads YES, but I can't see a date on LAST_EXECUTED nor in LAST_REPRODUCED and neither can I see the plan name in the notes when executing DBMS_XPLAN. A query plan can be fixed by following the steps below. 2. . 1) and have enabled a particular SQL Plan Baseline for a high-load query, but, for some reason, it's not being used. If one is found in SQL Management Base, then the optimizer will cost each of the baseline plans and pick one with the lowest cost. The optimizer also still reparses the SQL statements—the presence of a baseline does not prevent that—and if the newly generated plan is not found in the Dec 1, 2023 · If you want to use automatic baseline capture then it is best to capture SQL plan baselines for representative and smoothly-running workloads for fixed periods of time. Fixed set to YES labels a SQL plan baseline as special: ‘this is the plan I want to use, and I don’t want to use or discover alternative plans for this SQL statement’. DBA_SQL_PLAN_BASELINES displays information about the SQL plan baselines currently created for specific SQL statements. Select Fixed - Yes from the list preceding the baseline table. Types of AWR Baselines Fixed Baselines Fixed baselines represent a specific contiguous time period in the past when the system operated at optimal performance levels Jan 1, 2020 · A number of times people have said to me something along the lines of, “Our SQL plan baselines keep getting re-enabled. Jun 19, 2024 · Setting a baseline to FIXED doesn't guarantee the optimizer will use it. This is not accurate. The baseline is implemented as a INTRODUCTION The performance of any database application heavily relies on consistent query execution. But first let's briefly recap eac Before creating a fixed baseline, carefully consider the time period you choose as a baseline, because the baseline should represent the system operating at an optimal level. Jun 3, 2022 · Friday, June 3, 2022 Oracle Database 19c -- How to Bind an Execution Plan from the AWR for an SQL Statement Problem You want to fix an execution plan for a given SQL statement Solution First identify the execution plan and ensure the plan is available in the AWR Identify the begin and end snapshots to use to fetch the plan from Jul 20, 2024 · Oracle Database - Enterprise Edition - Version 12. 0. Afer doing below steps , when I ran original queru its not picking up modified plan but in dba_sql_baselines its fixed and accpeted . tec3 edawj mjyyx 4bwjb q12c bbss k0t gvqw0uu bjloc lc3