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Adaptive cursor sharing introduced in 11g R1 to address the bind peeking issues with things track especially the bind aware and bind sensitivity. This is for plan stability right, Read here more on this. Can this stability when bind peeking issues is be achievable in 10g, well the obvious answer is sql profiles, stored out […] Original and New Implementation for Nested Loop Joins Oracle Database 11g Release 1 (11.1) introduces a new implementation for nested loop joins. As a result, execution plans that include nested loops might appear different than they did in previous releases of Oracle Database. Both the new implementation and the original implementation for nested loop joins […] Well there are many sources to explain about the functionality of SQL Stored Outlines SQL Profiles SQL Performance Analyzer Adaptive Cursor Sharing SQL Plan Management Indeed all these tools are available to give the plan stability but with different ways. Basics:- Plan instability can occur due to bind value differences. Binds are used to reduce […] In general you will need to set the SQL trace or events (10046,10053) and run the problematic query and can obtain the sql execution statistics to trace files. or […] All, I have got a chance to speak about this nice cool feature in an other practical demo session to my colleagues, but few questions on the same remind to post and read something on this. Typically as usual my post flow, What, How, How to, Important note? What is SQL Monitoring? If a query […] We all know that Oracle Optimizer use object statistics to determine the cost of accessing that object. What if, if that object has missed statistics or the columns or the Hence Oracle introduced Dynamic sampling in 9i and has changed significantly through 11g. Definition:- Dynamic sampling augments missing or insufficient optimizer statistics. Using dynamic sampling […] What is cardinality? CBO estimate of the number of rows produced by a row source or combination of row sources. What are different types of cardinality? Cardinality Cardinality represents the number of rows in a row set. Here, the row set can be a base table, a view, or the result of a join […] Q: is it my possible to make my query to change from “select ‘what is my name’ from dual” to “select ‘you’r Geek DBA’ from dual” during execution. A: this feature is called “query equivalence”. query equivalence is declared using the dbms_advanced_rewrite.declare_rewrite_equivalence procedure, and uses the syntax: dbms_advanced_rewrite.declare_rewrite_equivalence(declaration_name,source_statement,target_statement); |
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Oracle 23c New Features for DBA's
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