Performance

Linking tableBASE

It is recommended that TBLBASE be statically linked, and not defined to CICS. By statically linking TBLBASE, the PPT is not searched for TBLBASE and the call is very efficient. If it is called dynamically, it must be defined to CICS.

Using the TB-PARM Communication Area

DataKinetics recommends using a TB-PARM Communication Area on every call to TBLBASE. If a TB-PARM is not used, performance can be significantly affected in some instances, for example, when DK1TCALL or DK1TROTB are in the LPA or an authorized library.

For this reason, if a TBPARM is not used on all calls to TBLBASE (or older APIs), we recommend that DK1TCALL, DK1TROTB and DK1TVROT not be placed in the LPA or an authorized library.

Application performance with TBASEV or TBCALLV

To improve the performance of applications using the V5 TBASEV or TBCALLV interface, relink the application modules with the V6 TBASEV or TBCALLV (now aliases for DK1TCALL).

Caching tableBASE library directory blocks

The tableBASE library directory can now be cached in memory. This can dramatically reduce the time needed to open a large number of tables when a TSR is initially loaded. tableBASE caching for a library is controlled by coding OPTCD=C on the DD statement for a library. This feature is currently not supported in a CICS region.

The library directory cache is not shared between regions. Thus caching can cause performance degradation in a region if the library is concurrently updated frequently by other regions. 

The use of VSAM buffers or external caching strategies is not supported for shared tableBASE libraries and may lead to data corruption.