Oracle Table Elimination

We have shown that table elimination is used in the Oracle query optimizer, at least since version 10gR2. It is also present in the Express Edition (XE). Both historized and non-historized attributes are eliminated from queries using the latest view, as shown in the proof of concept script found here.

In order to get table elimination to work in Oracle we had to rewrite the SQL-code for the latest view to suit PL/SQL. It should however be semantically equivalent to the Transact-SQL version used in SQL Server. Using AUTOTRACE to run some queries shows that the table elimination is in effect.

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Lars Rönnbäck

Co-developer of the Anchor Modeling technique. Programmer of the online modeling tool. Site maintainer. Presenter and trainer.

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