Integration: Relational Databases



The Omnidex SQL Engine will optimize queries to take advantage of the Omnidex indexes. Many queries can be fulfilled entirely within the Omnidex indexes. This is especially true for queries that request counts or aggregations from one or more tables. Even queries that return columns of data can be completed using the Omnidex indexes, as long as all of the requested data resides in an index.

Other queries will require access to the underlying Oracle data. The Omnidex SQL Engine will determine how to combine the results from the Omnidex indexes with the data from the Oracle database. Usually, this requires that Omnidex provide Oracle rowids or primary keys and request rows from the Oracle tables based on those values. Other times, Omnidex may issue a more complex statement to Oracle, asking it to perform a larger role in processing the query.

In all cases, Omnidex will access the data in the Oracle database using standard Oracle SQL statements issued using the Oracle Call Interface (OCI).

Oracle-specific Syntax

Omnidex requires that all statements use Omnidex SQL syntax. Omnidex SQL uses ANSI SQL as a base, but also allows extensions from various databases, as well as Omnidex-specific extensions. If the statement, SET SQL_SYNTAX ORACLE is issued, then Omnidex SQL will also support these Oracle-specific functions:

Other Oracle-specific syntax will cause errors when submitted to Omnidex. In these situations, the statements must be converted to Omnidex SQL.

Additional Resources

See also:

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integration/rdbms/oracle/queries.txt ยท Last modified: 2016/06/28 22:38 (external edit)