MCe maintains a table that tracks EVERY change that is made by MCe. It also tracks SELECT statement requests.

When reporting on the apsAuditLog table you are working with a table that could be as large as half the database or in theory even more, in practice it is trimmed from time to time, but it still can be huge, especially when images and files get involved.

As a result, being able to specify which rows to look at can save a lot of time for you and a lot of work for the SQL server.

Indexes to help make it more efficient

AuditServerUTC

If you just want to see the last x rows, or all the changes in a time period, this is an efficient way.

This index will likely be picked if your WHERE clause is something like: WHERE AuditServerUTC [NOT] BETWEEN '2021-03-09T10:59:99' AND '2021-03-09T13:00:00' to get all the records in the stated 1 hour period or WHERE AUditServerUTC > '2021-03-09T11:00:00', to get the most recent records assuming it is March 9th around noon when you run it.

Batch ID

This requires that you know the BatchID of course, but if you do know it this is extremely efficient. In most debugging situations this will be your 2nd or later call, not your first one, where your earlier call(s) gave you the BatchID and you want to see what other tables where affected by the same set of changes.

LaborID + AuditServerUTC

If your where clause has a known Labor and also, as above if you can also use a data range, filters by AuditServerUTC, you can use a wider range of date/times and still be very efficient.

If you just use LaborID in your WHERE clause this will be better than no index, but it could still be many many rows of data once the person has been using the system a while.

TargetSyncGUID+AuditServerUTC

If you are looking up the changes to a specific Asset or specific WO, first get it's GUID, then use this to find just the changes to that entity WHERE TargetSy5yncGUID = '22505537-10cc-417d-9c60-7fb67e343d56'. And also, as above, if you know the date/time range that you are interested in, filters by AuditServerUTC, you can use a wider range of date/times and still be very efficient WHERE TargetSy5yncGUID = '22505537-10cc-417d-9c60-7fb67e343d56' AND AuditServerUTC BETWEEN '2021-03-09T10:59:99' AND '2021-03-09T13:00:00'. since it will only be looking at rows with that specific TargetSyncGUID.

ID

the clustered index the most efficient index if you know the ID of the change you are looking for, though in most debugging situations you won't. This would be more common when you do a debugging session, record the IDs of interest, then come back later.