IBM Db2 Big SQL 7.1.0

UDX development best practices

Follow these best practices to create better, more robust UDXs.

Document each UDX
Employ caution when creating UDXs
Avoid name collisions
Avoid UDX linkage symbol collisions
Avoid "record size exceeded" errors
The API returns a record size exceeded error if the size of either the input or output exceeds 32,768 (32K) bytes.
Query optimization and UDX calls
Error reporting within a UDX
Within a UDX, use the throwUdxException() method to build in error checking and reporting capabilities. This method signals an error in the UDX and returns control back to the system.
Manage dynamic memory
Check for nulls
Manage source files that contain multiple functions
Keep backup copies of your UDX sources

Parent topic: C++ User Defined Extensions (UDX) class-based routines