Hi everyone,
Summary of the problem: I'm a beginner with SQL Server. For a project I need CDC to be turned on. I copy the cdc data to another (archive) database and after that the
CDC tables can be cleaned immediately. So the retention time doesn't need to be high, I just put it on 1 minute and when the cleanup job runs (after the retention time is already fulfilled) it appears that it only deleted a few records (the oldest ones). Why
didn't it delete everything? Sometimes it doesn't delete anything at all. After running the job a few times, the other records get deleted. I find this strange because the retention time has long passed.
Entire explanation of what I did: I set the retention time at 1 minute (I actually wanted 0 but it was not possible) and didn't change the threshold (= 5000). I disabled
the schedule since I want the cleanup job to run immediately after the CDC records are copied to my archive database and not particularly on a certain time.
My logic for this idea was that for example there will be updates in the afternoon. The task to copy CDC records to archive database should run at 2:00 AM, after this task the cleanup job gets called. So because of the minimum retention time, all the CDC records
should be removed by the cleanup job. The retention time has passed after all?
After a suggestion I just tried to see what happened when I set up a schedule again in the job (with a retention time of an hour this time), like how CDC is meant to be used in general. I had 3 records in that table. I changed 2 records at the same time and
a few minutes later another record. After the time has passed I checked the CDC table and turns out it also only deletes the oldest record. I set another schedule again and then it deleted another record (the 2nd record of the 2 that I updated at first).
Why aren't they purged all at once? What am I doing wrong?
I made a workaround where I made a new job with the task to delete all records in the CDC tables (and disabled the entire default CDC cleanup job). This works better as it removes everything but it's bothering me because I want to work with the original cleanup
job and I think it should be able to work in the way that I want it to.
Thanks,
Kim
PS. I made a tread like this in sql server 2014 yesterday, but it has like 10 views or so. I thought that this subforum would be appropriate as well. If it's not allowed, I can delete the other thread ofcourse.