Using LOB Locators in Transact-SQL Statements

Large object (LOB) locators let you indirectly reference a LOB in Transact-SQL statements rather than referencing the LOB itself.

Because the size of a text, unitext, or image LOB can be many megabytes, using an LOB locator in Transact-SQL statements reduces network traffic between the client and Adaptive Server, and reduces the amount of memory otherwise needed by the client to process the LOB.

Adaptive Server 15.7 allows client applications to send and receive locators as host variables and parameter markers.

When you create a LOB locator, Adaptive Server caches the LOB value in its memory and generates an LOB locator to reference it.

After a LOB locator is created, it remains valid for the duration of the transaction in which it was created. Adaptive Server invalidates the locator when the transaction commits or is rolled back.

LOB locators use three different datatypes

See "Using and Creating Datatypes" in the Transact-SQL Users Guide.