Before using tcACCESS there was no way to authenticate this information. With the help of tcACCESS, the customer is now able to integrate data from VSAM files into Microsoft Visual Basic applications via standard SQL queries. These applications perform processing and validation.

The customer wants to expand the applications in order to be able to change and maintain VSAM data from a Microsoft Visual Basic application.

Conclusion

tcACCESS is a powerful and versatile solution that enables open systems applications to perform direct SQL access to existing z/VSE and z/OS data resources (e.g. VSAM, IMS, DLI, ADABAS etc.) and mainframe applications direct access to Open Systems data permitted.

The challenge for this project is to keep the data in both system worlds synchronized in real time as far as possible. Only in this way is a phased replacement of the legacy system possible at all. The migration was implemented via mirror tables with the help of tcVISION to replicate the data from both platforms in both directions. The loopback procedure available in tcVISION ensures that changes to a system are not replicated back after adaptation in the target system.

After a short implementation phase, the project was phased into production.

Conclusion

The customer migrated to the new system environment more quickly than originally planned, thereby saving considerable costs for continued use of the old system. With the help of tcVISION, the customer's IT landscape was converted to the latest technologies and is therefore up to the challenges of the global economy.

The initial implementation consisted of nightly batch processing with the transfer of data extracted from Db2 or VSAM and transferred via FTP. However, this method quickly reached the limits of this form of processing. The batch window was not long enough to transfer the data and the customer ran the risk of not being able to meet the service level agreements.

The decision to replace the existing process was made with tcVISION. The changes in Db2 could be determined directly and in real time or via log files and transferred to the staging area. An analogous procedure was implemented for the VSAM files after batch processing. The tcVISION batch compare method was selected for this purpose.

Conclusion

The process went into production in a very short time and the expectations were more than met. On average, 6 hours of processing time per day were saved. The data is available to the department at 9 a.m. and all service level agreements are met. Another advantage was the drastic saving of mainframe resources through the use of tcVISION.

The customer is an international manufacturer of quality furniture. All materials management and bills of materials applications are own developments and tailored to the special requirements. The data is stored in hierarchical DL/I databases.

The aim is to implement materials management and parts list processing in the company network via web applications and to combine the information from the DL/I databases with the corresponding graphics from product planning.

The original plan to migrate from DL/I to a relational database was discarded for cost reasons. The decision in favor of tcACCESS was made on the basis of a reference visit to a tcACCESS customer.

tcACCESS represents the link between the mainframe and the web applications. The parts list information available in the DL/I databases can be retrieved from the web applications via SQL requests. The hierarchical DL/I data is thus treated like relational tables.

Information per application is stored in a MySQL database and specify which fields in the DL/I database should be accessed and whether SQL functions (e.g. SUBSTR, LEFT, etc.) should be used for certain columns, as well as color attributes of the values in the browser.

With the help of this information, the data is read and processed via tcACCESS. Changes in the DL/I databases (new or modified or deleted fields or segments) can thus be easily made in the SQL database without having to change the access programs.

The application is being used by the department and has been received very positively, especially the web interface and the associated options for easily linking components to one another.

Conclusion

The application has been received very positively by the department, especially the web interface and the associated options for easily linking components with one another.

The DL/I database became a relational database.

A new Windows word processing system is used company-wide in the user departments. All productive data is stored on the z/VSE mainframe under VSAM and DB2 and processed with CICS applications.

By using tcACCESS, the Windows word processing was integrated completely transparently into the CICS application.

The user works with a CICS application, e.g. the customer address data. The selection screen for over 400 different word processing templates is called up via a function key.

The desired form is selected. The CICS application starts the word processor on the user's workstation and passes the template name and a variable list containing mainframe data to a word processor macro. The macro reads the list of variables and inserts them into the desired document.

The finished word processing document can now be further processed individually by the user.

Conclusion

The transparent integration of a modern word processing into existing CICS applications was realized in a short time with tcACCESS and existing on-board resources. In addition, other operative solutions for the data center and the operating and work preparation staff have been created with tcACCESS.

The changes made in the productive DL/I databases in daily production operation by online users and through batch operation are captured by tcVISION in real time and written to a special Db2 table - or, if Db2 should not be active, to a VSAM file. These changes are processed at regular intervals and applied to the Db2 databases.

Once the migration is complete, changes in Db2 are also replicated from tcVISION to DL/i in order to comply with legal archiving regulations.

The daily change volume is more than 200,000 changes, at the peak more than 500,000.

Conclusion

Meanwhile, the customer has converted almost all applications to the new system and changes to the new system are still being maintained in the old system via tcVISION in order to meet all legal revision requirements. The use of tcVISION ensures orderly parallel operation.

The synchronization scenario is based on changed data capturing on the mainframe in real-time. The Adabas extension of tcVISION captures the changes and these changes are then propagated to a LINUX system using a mainframe collector and data pool storage. The LINUX system hosts an Oracle database that acts as a mirror of the Adabas databases. tcVISION directly propagates the mainframe changes into the Oracle database.

Both platforms act as equals (master/master). The tcVISION DBMS extension for Adabas captures changes on the mainframe in real-time and replicates those changes into an Oracle mirror database, from which the changes are applied to the Oracle production database.

The replication path from Oracle to Adabas on the mainframe is maintained through Oracle and the JDBC component of tcACCESS.

A tcACCESS Stored Procedure developed in PL/I obtains the Adabas Internal Sequence Number (ISN) for new inserted records for the Oracle environment.

The bidirectional replication guarantees that changes already applied on one of the platforms are not replicated back via the capturing mechanisms (tcVISION Loopback processing).

Log files are created to document the correct replication scenario.

Conclusion:

The bi-directional replication was a transparent migration of the applications. The Loopback method of tcVISION guranteed the correct synchronization between the ADABAS ISNs and the corresponding ORACLE tables fpr new record insertions.

The production implementation of tcVISION supports more than 370 Db2 tables. The operational changes to mirrored Db2 tables are replicated on the Windows replication server. The replication processes are part of the daily IT operations. The online systems and batch applications are responsible for the changes applied to Db2. All tables that are supposed to be replicated have the attribute ‘DATA CAPTURE CHANGES’ and all the changes are kept in the Db2 log. The log files are sent to the replication servers using FTP processes as soon as the online logs are archived by Db2. Once received, tcVISION processes the log files on the replication server. To process the log files and capture the changes, tcVISION has to understand the structures of the Db2 tables. This metadata is stored in a central repository which is also stored in the Db2. tcVISION provides import functions for creating the metadata from the Db2 source database. This metadata is used for the initial load of the Db2 tables to the server as well as for the processing of the Db2 log files.

The initial load of the Db2 tables on the replication server is performed by the BULK TRANSFER function of tcVISION. The input is a Db2 imagecopy that is sent to the replication server via FTP. The copy is processed and loaded to Db2 with the help of a LOAD statement generated by tcVISION. Then, the tables are available on the replication server and changes can be applied via the log file processing.

A special challenge was presented by the Db2 Compression Dictionaries and the fact that the structures of the tables can be changed during the daily operations. The information about the compression algorithm in use is scanned by tcVISION while importing the metadata and stored in the central repository. Each table is stored in a table space of its own. The different dictionary versions and corresponding compression algorithm are kept in the repository, so tcVISION can always use the correct algorithms for the decompression when processing the log files or imagecopies. The metadata reflects the structure of the data at the time of the import. tcVISION historicizes this structural information during a new import after a structure change. This way, tcVISION recognises changes of the data structure and is able to apply the changes to the target tables in accordance with the structure in place at the time the change was performed. That is why all Db2 structural information is refreshed every day by an automated process. This automated process guarantees the correct metadata and compression information to be used. tcVISION provides tools and utilities to delete all the historical repository entries that are no longer required.

Conclusion

The automatic daily processing and transfer of the Db2 changes to a data warehouse, as well as the provision of the Db2 changes on a mirrored system under Windows for evaluation purposes is implemented. Operational structural changes to the Db2 tables under z/OS are automatically recognized and taken into account by tcVISION.

The distribution of the subscription data is performed by tcVISION. The subscribed data is captured in real-time from the active log of a shared Db2 system on a z/OS system. The capture mechanism of tcVISION uses the Instrumentation Facility Interface of Db2. The changed data is transferred to an Intel based Linux system via TCP/IP, where the distribution of the data records to the customers is performed based on data record attributes.

Technically this was realised using a bit string as an integer attribute for the relevant tables. A comparison is performed for every replicated record by using a logical bit compare with different comparison values to check whether the record should be distributed to the customer. If the bit comparison is not successful, the record is rejected.

In addition to the bit string logic, a comparison based on a Lookup SQL and character string comparisons are performed. To serve each individual customer based on his requirements, a subscription system has been developed that only transfers the stock exchange values to which the customer has subscribed.

All processing definitions are stored in a central tcVISION repository.

Conclusion

Distribution of financial data to subscription customers. Each customer receives the data corresponding to their subscription.

With tcVISION, enormous amounts of data are constantly being propagated to customers. These large amounts of data (e.g. more than 2 million securities prices per day) can only be managed if the technology components used work perfectly and efficiently.