What is a Slot?

A slot is a narrow aperture or groove. The term is also used to refer to the position within a sequence or time line, as in “he slotted himself into the chair.”

A hole in the middle of a door, window, etc., that allows a latch or handle to be operated from either side. The term can also be applied to the opening created by a machine or mechanism, such as a computer disk drive slot, which allows data to be read or written into it.

In the context of airport coordination, a slot is an authorization for a planned aircraft operation at a particular airport during a specified time period. Air traffic controllers assign slots to avoid repeated delays caused by too many flights trying to take off at the same time.

A logical replication slot in PostgreSQL. A slot is a unique identifier that can be assigned to multiple consumers of the database change stream at any point in time and allows these consumers to receive changes on a consistent basis. A slot does not know which receiver is consuming its changes, and it does not necessarily correspond to the same physical slot in a database that is being replicated. This approach is useful when replicating from a large production database to several smaller test and development databases. It can also be used to implement a tiered architecture for sharing databases across a network. The word slot is derived from the Middle Low German word sleutana, referring to the cylindrical pin p screwed into the type-wheel S to create a slot in it.