Chapter 1: Meet the Transaction Log
In this chapter, we start with an overview of how SQL Server uses the transaction log, focusing on the Write Ahead Logging mechanism that ensures transactional consistency and durability during normal operation of a SQL Server database. We then offer an initial overview of two of the most significant ways in which it impacts the life of a DBA, namely database restore and recovery, and disk space management.
How SQL Server Uses the Transaction Log
In SQL Server, the transaction log is a physical file, identified conventionally, though not compulsorily, by the extension
LDF. SQL Server creates one automatically for any new database, along with the primary data file (commonly identified by the
MDF extension), ...