ECDA relies on the library path environment variable to locate necessary libraries, including the libodbc library and its library dependencies. During the build process, libraries become linked with other libraries that provide functions that the loading library uses, thus creating a runtime dependency; in other words, one library depends on the presence of another. As a result, the runtime loader must and load these other libraries to satisfy runtime dependencies. If it does not, the initial library load fails.The library path environment variables are:
Linux, Solaris, HP Itanium: LD_LIBRARY_PATH
AIX: LIBPATH
HP UX: SHLIB_PATH
When it uses the default ODBCDriverManager value, libodbc.xx, ECDA searches the library path and loads the first library found with the name matching the configuration property string, libodbc.xx. If the ODBCDriverManager library does not find its dependent libraries in its library path, the driver load fails and the ECDA start-up fails.
To find and load drivers, the OCBC Driver Manager uses configuration files, which contain information about target databases and driver location. All of the configuration files have an .ini extension (for example, odbc.ini) that can be identified by name and extension.
The environment variable identifier for the unixODBC driver manager is ODBCSYSINI, which points to the directory containing the odbc.ini and odncinstl.ini files, for example:
setenv ODBCSYSINI pathname
where pathname points to the odbc.ini file.
Configuration files that the ODBC Driver Manager uses have target database-specific information:
odbc.ini contains the data source name (DSN) information, which includes connection information, driver identifiers, and other driver-specific attributes.
odbcinst.ini contains driver-specific information.
