Matt Crowley (2/14/2014)
If you are updating 10 million rows, and the update takes 10 minutes, then the log entries (before and after pages) are written to the transaction log all throughout the 10 minutes.
Yes and no. The log records containing the before and after rows or row portions are written to the log buffer all throughout the 10 minutes and to disk when the log buffer flushes either because it's full or because some other transaction has committed or any of the dirty data pages need to be written to disk.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability