Integration: Relational Databases

Generic ODBC

Environments

The Omnidex Environment File contains metadata that describes the database and the Omnidex configuration. This includes the following connection and schema information for the underlying database:

  • ODBC system, user, or file datasource
  • ODBC user and password
  • ODBC schema information tables, columns, and datatypes
  • ODBC primary and foreign key constraints
  • ODBC native indexes

Generating an Omnidex Environment File

Omnidex can automatically generate the CREATE ENVIRONMENT, CREATE DATABASE, CREATE TABLE, and CREATE INDEX statements needed for an Omnidex Environment File. The EXTRACT statement will connect to the underlying database using ODBC, query the database's schema information, and generate the appropriate statements. The EXTRACT statement can be issued through OdxSQL, or through any ODBC or JDBC application.

extract       DDL
  for         ODBC
  to          "simple.sql"
  with        DSN="simple"
              USER="simple"
              PASSWORD="simple"
              DATABASE="simple"
              INDEX_DIRECTORY="idx"


The following options from the EXTRACT SQL statement are used to provide ODBC connection information and control the output of the statement. These options also correlate with the options of the CREATE DATABASE statement.

DSN or FILEDSN

The DSN option references a system or user datasource for the underlying database, and the FILEDSN option references a file datasource for the underlying database. These datasources are created using the instructions provided by the underlying database.

USER

The user to be used when accessing the underlying database through ODBC. One user and password is used when connecting to the ODBC database. That login determines that security access to the database and the visibility of the underlying database objects. This option is required unless a user and password is included in the datasource.

PASSWORD

The password to be used when accessing ODBC. This password must correspond to the user referenced in the USER option. This option is required unless a user and password are included in the datasource.

DATABASE

The DATABASE option controls the logical database name to be recorded in the Omnidex Environment File for this database. This is not an ODBC setting, but rather a logical name given to the database for use in Omnidex statements. This option is required.

TABLES

The TABLES option controls the table schema information to be extracted from ODBC. The TABLES option can include a comma-separated list of tables or “*” to extract all tables. If this option is omitted, then all available tables are extracted.

INDEX_DIRECTORY

The INDEX_DIRECTORY option declares the directory to contain the Omnidex indexes. This is not an ODBC setting, but rather a path designation where indexes should be built. This directory can include either absolute or relative path designations. If this option is omitted, then the indexes will be built in the same directory as the Omnidex Environment File.

Limitations of the Omnidex EXTRACT statement

The extracted CREATE statements represent the best translations that can be automatically generated by querying the underlying database through ODBC; however, these statements may require edits by the administrator. Edits that may be required include:

  • ODBC object names, such as tables, columns, constraints or indexes, are reduced to 32 bytes in length for use in Omnidex.
  • ODBC Wide Character datatypes, which are commonly used to store Unicode data, are shown as CHARACTER or STRING datatype, as these are the most universal datatypes in an Omnidex application. If necessary, these can be changed to Omnidex NCHARACTER or NSTRING datatypes.

Manually Creating an Omnidex Environment File

An Omnidex Environment File can also be created by manually issuing CREATE ENVIRONMENT, CREATE DATABASE, CREATE TABLE, and CREATE INDEX statements in OdxSQL or using ODBC or JDBC. If these statements are written to a text batch file, then that file can be submitted to OdxSQL using the USE command.

Additional Resources

See also:

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