According to this article, http://resources.arcgis.com/en/help/main/10.1/index.html#/ST_Transform/006z0000009s000000/, to apply file-based CRS transformation in using sde.st_transform function, need to copy the ArcGIS pedata folder to the database server and setup environmental variable PEDATAHOME on the database server. It gives an example for databases on Windows. I am wandering if anybody has done this for SDE database on Linux and what else needs to be done. Does the database instance needs to be rebounced or the listener needs some extra configuration? The st_geometry functions work fine on our system, it is just how we can use file-based CRS transformation, such as from NAD27 to WGS_1984_UTM_Zone_15N with NAD_1927_To_WGS_1984_79_CONUS datum transformation in sde.st_transform function.