(This post first appeared on SQLperformance.com four years ago as part of a blog series, before that website was mothballed later in 2022 and the series was curtailed. Reposted here with permission, with a few tweaks.)
All through my career as a data professional, both inside Microsoft and as a consultant, I’ve found that one of the most misunderstood parts of SQL Server is the transaction log. Lack of knowledge of how the transaction log works and needs to be managed, or just simple misconceptions, can lead to all kinds of production problems, including:
The transaction log growing out-of-control