L

Latency

The delay in time for a data change to be propagated between nodes in a replication topology.

Linked report

A report in SQL Server Reporting Services that takes its definition through a link to another report.

Linked server

An OLE DB data source used by SQL Server distributed queries.

Locking

A mechanism used by a concurrent system to prevent data anomalies by isolating transactions from each other.

Log file

See Transaction log files.

Log reader agent

The replication agent that monitors the transaction logs of each database configured for transactional replication and searches for transactions that need to be replicated.