What is a table lock?

Environment:

All Sites, All versions.

Issue:

Locked database tables, often seen via "Locked" error or warning messages.

Cause/Resolution:

A table, or portion of a table, that is inaccessible for a period of time is a normal part of the use & operation of a database. When the database is using a portion of a table, that portion id first locked, ensuring that another process cannot attempt to make changes to it at the same time.  Some examples of things that can cause table locks:

• Backups being performed.
• Multiple reports running on the replication server.
• Poorly formed database queries being run against the replication server.