SCI - Technical Article - SPAM Errors Reported by DBO/VERIFY/ONLINE

Q:

When running DBO/VERIFY/ONLINE, we receive the following error messages:

"DBO-W-PGSPAMENT, area <str>, page <int>; the <int>% fullness value for this data page does not fall within the <int>-<int>% range found on the space mgmt. page."

However, if we run DBO/VERIFY standalone on the same database the error messages do not appear. What are we doing wrong?

A:

The problem you are experiencing is a timing problem. The DBO/VERIFY/ONLINE operation uses batch retrieval (snapshot files) to ensure a consistent view of the database during the online verify. However, the snapshot files contain only storage-area line entries (records), not the SPAM pages or SPAM entries for each page.

Since the SPAM entries are updated as records are being added, deleted or modified during the online verification operation, the updated SPAM values are not being written to the snapshot files. Although there are no perfect solutions to this problem, there are a couple of ways that you can eliminate or minimize the impact:

Run DBO/VERIFY on a copy of the database restored from the most recent backup. This solution has the advantage that it not only verifies the internal integrity of your database, but it also validates the integrity of your DBO/BACKUP and media. The obvious downside to this solution is the time and space required to implement it.
To minimize the impact of this problem in your environment, you should schedule your DBO/VERIFY/ONLINE to run during low update periods. This makes sense for all /ONLINE operations since it will reduce the overhead of the /ONLINE process.