basic tlog question

whenever a transaction or a SQL statement executes, do the changes get
written to the log file first ? I know they do, but are they also in
memory.. I understand the part where dirty pages are written to disk.. at
checkpoints or lazy writers or thru worker threads...what im a bit confused
is when it talks about writing to disk, is it referring to the data files on
disk or the log files on disk..
Can someone just give me a 2 to 3 liner on the initial part before the data
actually gets written to the disk i.e. disk that contains the data files ?Yes, the log records are written to memory too, to an area called 'log
cache', and SQL Server has a logic to make sure these cached log records are
written to log files, before the associated dirty pages are written to disk.
--
Vyas, MVP (SQL Server)
http://vyaskn.tripod.com/
"Hassan" <fatima_ja@.hotmail.com> wrote in message
news:e3WwGOvaEHA.3524@.TK2MSFTNGP12.phx.gbl...
> whenever a transaction or a SQL statement executes, do the changes get
> written to the log file first ? I know they do, but are they also in
> memory.. I understand the part where dirty pages are written to disk.. at
> checkpoints or lazy writers or thru worker threads...what im a bit
confused
> is when it talks about writing to disk, is it referring to the data files
on
> disk or the log files on disk..
> Can someone just give me a 2 to 3 liner on the initial part before the
data
> actually gets written to the disk i.e. disk that contains the data files ?
>