Integration: Relational Databases

Environments and Relational Databases

Omnidex provides access to a relational database by creating an Omnidex Environment File that points to the relational database and the tables. Within the Omnidex Environment File, the administrator declares a database with connection information for the underlying relational database, and then declares tables that point to the underlying relational tables or views. Note that the Omnidex Environment File contains only metadata, and does not make a copy of the data in the relational database.

Declaring Relational Objects

Omnidex only has access to the tables and columns that are declared in the Omnidex Environment File. Any database objects that exist in the underlying relational database, but are not declared in the Omnidex Environment File, are unknown to Omnidex. This allows administrators to control the visibility of the relational database as needed. The Omnidex Environment File can also be used to alter the metadata. Objects can have different names within Omnidex, and some datatypes can be changed as well.

The Omnidex Environment File should not only declare the tables and columns, but it should declare the table constraints and native indexes as well. Primary and foreign key constraints should be declared with each table so that Omnidex can understand the parent-child table relationships in the database. Relational database indexes should be declared as NATIVE indexes so that Omnidex can understand what optimization is possible at the relational database level. These constraints and native index declarations are important for Omnidex query optimization.

Combining Raw Data Files and Relational Databases

Raw data files often supplement a relational database. For example, a transaction log or a supplemental data file may contain information that is ideal to correlate with a relational database. Companies importing that data into the relational database can avoid the extra work, and use Omnidex to join those two data sources together instead.

An Omnidex Environment File can include more than one database, and each database can be of a different type. An Omnidex Environment File can have one database that points to the underlying relational database, and a second database that points to a series of raw data files. When connected to this Omnidex Environment File, applications can issue SQL statements that join tables from both databases.

Once connected to this Omnidex Environment File, statements can be issued that reference all of the tables in the environment, including referencing tables from both databases.

Additional Resources

See also:

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