STACK (C)
Use the STACK modifier with a C UDR to override the default stack size that the STACKSIZE configuration parameter specifies.
The STACK modifier specifies the size (in bytes) of the thread stack, which a user thread that executes the UDR uses to hold information such as routine arguments and returned values from functions.
A UDR needs to have enough stack space for all its local variables. For a particular UDR, you might need to specify a stack size larger than the default size to prevent stack overflow.
When a UDR that includes the STACK modifier executes, the database server allocates a thread-stack size of the specified number of bytes. Once the UDR completes execution, subsequent UDRs execute in threads with a stack size that the STACKSIZE configuration parameter specifies (unless any of these subsequent UDRs have also specified the STACK modifier).
For more information about the thread stack, see your HCL OneDB™ Administrator's Guide and the HCL OneDB DataBlade® API Function Reference.