Optimization

Omnidex will attempt to optimize queries to run in the most efficient manner by using the indexes. This section discusses various scenarios, showing exactly how they were or were not optimized.

The best tool for ensuring optimized queries is the Omnidex utility ODXSQL. ODXSQL can produce an Explain Plan for all queries, detailing the exact steps Omnidex took to process the query. The Explain Plan lists how a query was optimized, if applicable, provides warnings on potential problems as well as other detailed information that may assist in refining queries to run as efficiently as possible. The information provided by the Explain Plan can then be used to help "tune" the query or the indexes to ensure optimal performance.

If the index installation does not match the query criteria specification, assuming the query syntax is valid, the query will still be processed. Omnidex will attempt to optimize the query as much as possible.

One-Pass vs Deferred Optimization

One-pass optimization is Omnidex's ability to completely process a query without physically touching the database until the final qualified row retrieval. This means that all of the given criteria is satisfied and a final qualified list can be produced entirely within the indexes.

Deferred optimization means that at some point while processing the query, Omnidex was forced to retrieve some data from the database before it could completely satisfy all of the given criteria. This does not mean that the query is not optimized, however. It simply means that the query had to be broken into multiple pieces, but each piece on its own, may still be optimized.

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