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All posts by Lazhar Felahi

Lazhar Felahi



Lazhar Felahi

SQL Tuning – Mix NULL / NOT NULL Values

By | Development & Performance, Oracle | No Comments

One of the difficulty when writing a SQL query (static SQL) is to have in the same Where Clause different conditions handling Null Values and Not Null Values for a predica. Let’s me explain you by an example : Users can entered different values for a user field from an OBI report: – If no value entered then all rows must be returned. – If 1 value entered then only row(s) related to the filter…

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Lazhar Felahi

Where come from Oracle CMP$ tables and how to delete them ?

By | Database Administration & Monitoring | No Comments

Regarding the following “MOS Note Is Table SCHEMA.CMP4$222224 Or Similar Related To Compression Advisor? (Doc ID 1606356.1)”, we know that since Oracle 11.2.0.4 BP1 or Higher, due to the failure of Compression Advisor some tables with names that include “CMP”, created “temporary – the time the process is running” by Compression Advisor process (ie CMP4$23590) are not removed from the database as that should be the case. How theses tables are created ? How to…

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