Checkpoint completeness

[Former Member]

Hi all,

how can I be sure that after a checkpoint in SA12, log file contains exactly all my updated data?

I verified that even using a simple CHECKPOINT statement, my log file is not updated to the last modify applied to DB.

I proof even to decrease the checkpoint_time option from 60 min. to 1 min. but even in this case, it has been necessary wait several minutes to view my changes applied to my DB.

I have used -a dbsrv12 option on a different DB to verify all my changes was applied.

Kind Regards Vito Degirolamo

[Breck_Carter]

Point 1: I am sure you did not confuse "checkpoint log" with "transaction log"... but as a warning to other folks: Checkpoint and Commit aren't in the same ballpark, they aren't in the same league, they aren't even in the same sport.

Point 2: The Help topics "Checkpoint statement" and "Commit statement" are [ahem] less than thorough. Some detailed information is located in other Help topics, but the subject deserves a 100-page white paper (that's not as bad as "How Cursors Work" which deserves 1000 pages 🙂

Point 3: While you're waiting for the White Paper, you can search for existing documents here: http://sqlanywhere.blogspot.ca/2012/06/sql-anywhere-advanced-search.html

Point 4: Checkpoint and commit operations are only loosely connected, and there's a huge and extremely confusing mess of operations going on behind the scenes. Glenn hints at the complexity 🙂

Now, the $64,000 question... did you do a commit and wait for it to finish before looking at the transaction log?