Running a database with the -i startup parameter causes
fewer data and before-image blocks to be written to disk. Running with No Crash Protection (no-integrity) makes I/O intensive operations run much faster, such as binary load operations. This is because when running with the -i (no-integrity) startup flag (-i forces -R) - Buffered Synchronous I/O (O_RDWR) to the bi file and no bi/data order synchronization occurs. For further discussion refer to Article
Does Progress use Synchronous or Asynchronous I/O? This means that if the database were to crash or a user get killed
even if the system were not to crash as a result, there is no guarantee that crash recovery will complete. In this case, we don't even try to recover, the database is inaccessible:
** The last session was run with the no integrity (-i) parameter. (509)
** Your database cannot be repaired. You must restore a backup copy. (510)
No Crash Protection (-i) should never be used unless a valid/complete backup exists. Should the database crash while running with No Crash Protection, the database will not be able to go through crash recovery. The only recourse when this happens is to revert to backup. Refer to Article
Database errors 509 and 510 after abnormal shutdown using no crash protection (-i) parameter The no-integrity (-i) option should not be used with a database that has AI enabled. Refer to Article
No integrity and AI files Understanding the risks, performance is vastly improved running with no integrity (-i) and should be used for distinct I/O intensive operations. For example: