Doublt related to : optimizer_use_sql_plan_baselines parameter

From: Eriovaldo Andrietta <ecandrietta_at_gmail.com>
Date: Sat, 2 Dec 2017 10:25:46 -0200
Message-ID: <CAJdDhaNFcXJ1W2HWzTpw8VGLSThQds8oZLj4J35V9Q_kG_F=Kw_at_mail.gmail.com>



Hello :

I am using Oracle 12C R1 and when the parameter below was equal TRUE

SQL> show parameter optimizer_use_sql_plan_baselines

NAME                                 TYPE        VALUE

------------------------------------ -----------
------------------------------
optimizer_use_sql_plan_baselines boolean TRUE

This statment sql belows was the top in the AWR :

SELECT obj_type, plan_id, statement_id, xpl_plan_id, timestamp, remarks, operation, options, object_node, object_owner, object_name, object_alias, object_instance, object_type, optimizer, search_columns, id, parent_id, depth, position, cost, cardinality, bytes, other_tag, partition_start, partition_stop, partition_id, other, distribution, cpu_cost, io_cost, temp_space, access_predicates, filter_predicates, projection, time, qblock_name, EXTRACTCLOBXML(other_xml, '/*/outline_data') outline FROM sqlobj$plan WHERE signature = :1 AND category = :2 ORDER BY signature, category, obj_type, plan_id, id

So the parameter was changed to FALSE, and this query did not appear as the TOP in AWR.

I got information that it is a bug. The patch for this bug is applied in the instance.

Now the instance is running with parameter = FALSE.

My doubts area :

The execution plan is being done correct and in the best way ? We donĀ“t use baselines for sql_id (DBMS_SPM) for queries. What is the impact using this parameter = FALSE ? Is it bad ?

Regards
Eriovaldo

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http://www.freelists.org/webpage/oracle-l Received on Sat Dec 02 2017 - 13:25:46 CET

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