Oracle GoldenGate 12c Implementer's Guide

Managing the trail file

In a busy database environment, redo data generation can increase significantly, particularly with the required supplemental logging enabled on your source tables. As we know, an Oracle database will recycle its redo logs in a round-robin fashion, switching to the next log when full. GoldenGate scans the redo logs and writes its own trail files to the dirdat subdirectory. Although the trail file data is typically a quarter the size of its equivalent redo data, if left unmanaged, the volume of files in dirdat can be significant. In the worst case scenario, filling the filesystem to 100 percent utilized. Obviously, this is not ideal, so GoldenGate has provided its own automated mechanism to purge trail files from this area. ...