When you do a backup, markers are written to the Transaction Log file, however, the backup process does not change anything about the datafiles -therefore the 'trn' file gets a new datetime and the data file does not.
The Transaction Log file does not shrink UNLESS specifically so instructed. See Books Online for DBCC 'Shrinkfile'.
|||Hi,
You can schedule half/hourly t-log backup to keep it in shape, how ever if its growing unpexctingly refer below thread:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=1221599&SiteID=1
Hemantgiri S. Goswami
|||What we are seeing are current timestamps on the trn file, current timestamps on the ldf, but about a six month old modified date on the mdf. I would assume that the trn file would have the most recent transactions, the ldf the intermediate, and then the mdf.
With the truncate command on the trn file, do the transactions immediately hit the mdf file or the ldf (I would think the ldf)? however when does the mdf get updated by the ldf file?
Am I completely lost--I thought that the ldf (a locked mdf file, correct?) would eventually post the edits/updates to the mdf.
|||The ldf is the transaction log file. Data changes are moved to the mdf (data file) on a regular basis -usually within seconds.
The OS stamps the file date. SQL Server has a data file (mdf) open with a, perhaps, large, amount of empty space. The OS does not know what is happening inside the mdf file unless there are specific interactions between SQL Server and the OS regarding the file.
It seems like you are confused because the mdf file date is not changing. It most likely will not change unless one of the following actions occur: Filegrowth, Fileshrink, Detach/Attach.
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