Database driver specification (driver)

In database connection parameters, the driver parameter identifies the type of database driver to be used.

We distinguish two types of database driver names:

• Generic driver names ("dbmora", "dbmsnc"), and aliases ("oracle", "sqlserver")
• Version-stamped driver names ("dbmora_12", "dbmsnc_10", "dbmsnc_11")

A driver name "dbmxxx" identifies a generic driver name for the database server identified by the code xxx.

For example, in FGLPROFILE, to define the database driver for the Oracle OCI client (code "ora"), use the name "dbmora":

dbi.database.stores.driver = "dbmora"

The generic driver names (like dbmora) require the latest database client software available on the platform. This can change from one Genero BDL release to another, when supporting a new database client version. Use the version-stamped driver name (like dbmora_12), to point to a specific database client version, for example when the most recent database client software is not available on the platform.

$ ldd $FGLDIR/dbdrivers/dbmmys.so
      ...
      libmysqlclient.so.21 => ...
      ...

Drivers with generic names are compatible with the latest database client version available on the platform. Depending on the platform, the same generic driver name can refer to different database client software versions. For example, on an old platform where only MySQL 5.7 client is available, dbmmys will identify the dbmmys_5_7 driver. On a more recent platform where MySQL 8.0 is available, dbmmys will identify the dbmmys_8_0 driver.

To limit the number of drivers, if the database client software allows it, the drivers are build with the oldest database client version that is compatible with the latest available database client versions. For example, the dbmdb2_10 driver is linked to libdb2.so.1, which is supported by the IBM DB2 V10 and V11 client software.

Note that a given driver (combined with the corresponding database client software) can connect to a database server of an older version, if the database vendor client/server protocol supports the combination. For example, you can use an Oracle client version 12c to connect to an 11g server. The ODI driver will then adapt SQL translations and emulations to the target database server.

A default driver can be specified with the dbi.default.driver FGLPROFILE entry. This driver will be used for all database connections that do not specify the driver explicitly:

dbi.default.driver = "dbmora"

If this entry is not defined, and if no driver parameter is specified for the data source, the driver name defaults to dbmdefault. This default driver is a copy of the database driver that was chosen during installation.