You only have a single odbc.ini. The driver manager that gets used is the one shipped with SAS/ACCESS Interface to Redshift. There is a special interaction between SAS and the driver manager that allows the driver manager to load other drivers. This is all explained in the last paragraph of the SAS/ACCESS Interface to Redshift section of the Configuration Guide for SAS 9.4 Foundation for UNIX Environments. I'd not use odbcinst, or any of the other tools shipped with the unixODBC driver manager in this case because the driver manager shipped within SAS/ACCESS Interface to Redshift is not based on unixODBC.
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