References to LOB or XML variables
You can define regular LOB or XML variables, LOB or XML locator variables, and LOB or XML file reference variables.
Regular LOB or XML variables, LOB or XML locator variables, and LOB or XML file reference variables can be defined in the following host languages:
- C
- C++
- ILE RPG
- ILE COBOL
- PL/I (LOB only)
Where LOBs or XML are allowed, the term variable in a syntax diagram can refer to a regular variable, a locator variable, or a file reference variable. Since these variables are not native data types in host programming languages, SQL extensions are used and the precompilers generate the host language constructs necessary to represent each variable.
When it is possible to define a variable that is large enough to hold an entire LOB or XML value and the performance benefit of delaying the transfer of data from the server is not required, a LOB or XML locator is not needed. However, it is often not acceptable to store an entire LOB or XML value in temporary storage due to host language restrictions, storage restrictions, or performance requirements. When storing a entire LOB or XML value at one time is not acceptable, a LOB or XML value can be referred to by a LOB or XML locator and portions of the LOB or XML value can be accessed.