Jul 15

OCM 11g Preparation – Use SQL Tuning Advisor

SQL Tuning Advisor is a great tool. This item is related with the previous topic (“Use SQL tuning tools and features“), but was defined separately. This indicates that it is very important and will probably be in the certification exam. SQL Tuning will suggest you to: Create a SQL Profile Create an Index Gather Statistics Restructure SQL …

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Jul 15

OCM 11g Preparation – Use SQL tuning tools and features

This chapter is very very hard. Why? Because you can rephrase this as: “you need to know all the oracle tools that can help you improve the performance of something”. So, what are those “tools” and “features”. Well, there are a lot of them: First, the ones that have a specific topic already defined: SQL Performance …

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Jul 09

OCM 11g Preparation – Interpret execution plan

As the topic before, execution plans are another thing that just the practical experience will give you knowledge. Studying through docs is not a good approach to learn that, at least for me. After you get the basic concepts, try to check and understand what and why is happening. Study also: Creating Plan Table. Set explain from …

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Jul 09

OCM 11g Preparation – Administer and tune schema object to support various access methods

Access Methods (or Paths) are something totally related to the optimizer. So, what you should study here are the access methods that are possible inside Oracle for either Tables, B-Tree Indexes, Bitmap Indexes or Clusters: Full Table Scans Table Access by Rowid Sample Table Scans Index Unique Scans Index Range Scans Index Full Scans Index Fast …

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Jul 08

OCM 11g Preparation – Administer Resource Manager

Resource Manager is very very useful when you want to limit your system resources. Sometimes you can have a session that is out of control taking all your parallels servers or consuming a lot of CPU and I/O. Or even if you want to limit (“give a quota”) the UNDO tablespace consumption by someone. So, …

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