What is the LDF file in SQL Server?

Question

What is the LDF file in SQL Server? what is its purpose?

can I safely delete it? or reduce its size because sometimes it\'s 10x larger than the database file mdf.

Answer 1

The LDF file holds the database transaction log. See, for example, http://www.databasedesign-resource.com/sql-server-transaction-log.html for a full explanation. There are ways to shrink the transaction file; for example, see http://support.microsoft.com/kb/873235.