This section describes the example stored procedure NDBPURGN, a Natural subprogram which purges Natural objects from the buffer pool used by the Natural stored procedures server.
This section covers the following topics:
The example stored procedure NDBPURGN comprises the following text members which are stored in the Natural system library SYSDB2:
| Member | Explanation |
|---|---|
| CR5PURGN |
Input member for SYSDB2 ISQL. Contains SQL statements used to declare NDBPURGN in DB2 Version 5. |
| CR6PURGN |
Input member for SYSDB2 ISQL. Contains SQL statements used to declare NDBPURGN in DB2 Version 6 and above. |
| NDBPURGP | The client (Natural) program which
|
| NDBPURGN |
The stored procedure which purges objects from the buffer pool. NDBPURGN invokes the application programming interface USR0340N supplied in the Natural system library SYSEXT. Therefore, USR0340N must be available in the library defined as the steplib for the execution environment. |
To define the example stored procedure NDBPURGN
Define the stored procedure in the DB2 catalog by using the SQL statements provided as text members CR5PURGN (for DB2 Version 5) and CR6PURGN (for DB2 Version 6).
Specify the name of the Natural stored procedure stub (here: NDB41SRV) as LOADMOD (V5) or EXTERNAL NAME (V6). The Natural stored procedure stub is generated during the installation by assembling the NDBSTUB macro.
As the first parameter, pass the internal Natural parameter STCB to the stored procedure. The STCB parameter is a VARCHAR field which contains information required to invoke the stored procedure in Natural:
The program name of the stored procedure and the library where it resides,
The description of the parameters passed to the stored procedure and
The error message created by Natural if the stored procedure fails during the execution.
The STCB parameter is generated automatically by the CALLMODE=NATURAL clause of the CALLDBPROC statement and is removed from the parameters passed to the Natural stored procedure by the server stub. Thus, STCB is invisible to the caller and the stored procedure. However, if a non-Natural client intends to call a Natural stored procedure, the client has to pass the STCB parameter explicitly. See also Stored Procedure Control Block below.
Below is the Stored Procedure Control Block (STBC) generated by the CALLMODE=NATURAL clause as generated by the stored procedure NDBPURGN before and after execution. Changed values are emphasized in boldface:
004C82 0132F0F3 F0F6E2E3 C3C2F3F1 F040C8C7 *..0306STCB310 HG* 11097D42 004C92 D2404040 4040C8C7 D2404040 4040D5C4 *K SAG ND* 11097D52 004CA2 C2D7E4D9 C7D74040 40404040 4040F0F5 *BPURGP 05* 11097D62 004CB2 F7F0D5C4 C2D7E4D9 C7D5F0F0 F0F6F0F9 *70NDBPURGN000609* 11097D72 004CC2 F9F9F940 40404040 40404040 40404040 *999 * 11097D82 004CD2 40404040 40404040 40404040 40404040 * * 11097D92 004CE2 40404040 40404040 40404040 40404040 * * 11097DA2 004CF2 40404040 40404040 40404040 40404040 * * 11097DB2 004D02 40404040 40404040 40404040 40404040 * * 11097DC2 004D12 40404040 40404040 40404040 40404040 * * 11097DD2 004D22 40404040 40404040 40404040 40404040 * * 11097DE2 004D32 40404040 40404040 40404040 40404040 * * 11097DF2 004D42 40404040 40404040 40404040 40404040 * * 11097E02 004D52 40404040 40404040 40404040 40404040 * * 11097E12 004D62 40404040 40404040 40404040 40404040 * * 11097E22 004D72 40404040 40404040 40404040 40404040 * * 11097E32 004D82 40404040 40404040 40404040 40404040 * * 11097E42 004D92 40404040 D4C1F86B F0D4C1F4 F06BF0D4 * MA8,0MA40,0M* 11097E52 004DA2 C2F26BF0 D4C2F26B F0D4C9F2 6BF0D4C9 *I2,0MI2,0MI2,0MI* 11097E62 004DB2 F26BF04B *2,0. * 11097E72
004C82 0132F0F3 F0F6E2E3 C3C2F3F1 F040C8C7 *..0306STCB310 HG* 11097D42 004C92 D2404040 4040C8C7 D2404040 4040D5C4 *K SAG ND* 11097D52 004CA2 C2D7E4D9 C7D74040 40404040 4040F0F5 *BPURGP 05* 11097D62 004CB2 F7F0D5C4 C2D7E4D9 C7D5F0F0 F0F6F0F0 *70NDBPURGN000600* 11097D72 004CC2 F0F0F040 40404040 40404040 40404040 *000 * 11097D82 004CD2 40404040 40404040 40404040 40404040 * * 11097D92 004CE2 40404040 40404040 40404040 40404040 * * 11097DA2 004CF2 40404040 40404040 40404040 40404040 * * 11097DB2 004D02 40404040 40404040 40404040 40404040 * * 11097DC2 004D12 40404040 40404040 40404040 40404040 * * 11097DD2 004D22 40404040 40404040 40404040 40404040 * * 11097DE2 004D32 40404040 40404040 40404040 40404040 * * 11097DF2 004D42 40404040 40404040 40404040 40404040 * * 11097E02 004D52 40404040 40404040 40404040 40404040 * * 11097E12 004D62 40404040 40404040 40404040 40404040 * * 11097E22 004D72 40404040 40404040 40404040 40404040 * * 11097E32 004D82 40404040 40404040 40404040 40404040 * * 11097E42 004D92 40404040 D4C1F86B F0D4C1F4 F06BF0D4 * MA8,0MA40,0M* 11097E52 004DA2 C2F26BF0 D4C2F26B F0D4C9F2 6BF0D4C9 *I2,0MI2,0MI2,0MI* 11097E62 004DB2 F26BF04B *2,0. * 11097E72
