The documentation indicates that asbackup will break up the output records into files of 200K records each.
Question: Is asrestore similarly limited to this 200K record limitation. Or could we create a much larger .asb file with say, 2M records, and pass that into asrestore?
We put 200K restriction per file, which helps in parallelism while doing restore. There is no such limitation in asrestore. Multiple files with 200K record helps in restoring records in parallel.