More about trail files
Trail files are used by Extract and Replicat processes; their primary role is for data persistence. You could argue that writing files to what could be deemed as a staging area is wasteful and suboptimal. Having said that, GoldenGate writes only the committed transactions to trail files in large blocks minimizing I/O. Furthermore, the architecture provides a guaranteed no data loss solution that is not to be underestimated.
The trail
By default, trail files are in the canonical format being unstructured, but with a header record. They are stored in the ./dirdat subdirectory under the GoldenGate Home. Each record contains the changed data and is of a variable record length. A trail can contain numerous trail files, each having ...
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