tcVISION Frequently asked questions
Frequently asked questions
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FAQ - Frequently asked questions

  • tcVISION is a powerful change data capture (CDC) platform for users of IBM mainframes and Open System servers. tcVISION automatically identifies the changes applied to mainframe and Open System databases and files.
  • No programming effort is necessary to obtain the changed data. tcVISION continuously propagates the changed data to the target systems in real-time or can perform the process in time intervals.
  • tcVISION offers a rich set of processing and controlling mechanisms to guarantee a data exchange implementation that is fully audit proof.
  • tcVISION contains powerful bulk processors that perform the initial load of mass data or the cyclic exchange of larger data volumes in an efficient, fast and reliable way.

Here you will find answers to the most frequently asked questions about tcVISION

Why has tcVISION been developed?

The growing number of distributed application systems that maintain their individual databases as well as the mobility of applications demand an ongoing exchange of data between mainframe and Open System server.

In a market with no borders and no time limits the end-user demands highly accurate and timely accurate information. Innovative solutions for an ongoing information exchange between the individual application systems are required to implement the "Real-Time Enterprise".

Why should a corporation use tcVISION?

The number of applications that operate a database is increasing and the demand to constantly synchronize data between the mainframe and Open System platforms becomes a critical operational issue. This is even more important if a bidirectional synchronization is required.

The traditional methods for the exchange of mass data faces limits (limited batch windows) and the general cost pressure requires efficient solutions for data exchange, data synchronization and data replication.

What methods are provided to capture the changed data?

tcVISION supports different "capture" methods. These methods can be individually used as application and data processing flow requires it.

Real-time/Near Real-time – DBMS Extensions

The changed data will be determined using database exits. These are the standard exits provided by the DBMS. The changed data can either be processed through tcVISION pools or via z/OS logstreams created by tcVISION.

Real-time/Near Real-time – z/OS Logstreams

The changed data will be determined through the processing of z/OS logstreams. z/OS logstreams may be available for VSAM/CICS or Shared VSAM in a Coupling Facility environment. Logstreams can also be created by the tcVISION DBMS Extensions.

Log Processing

The changed data is selected and processed from the active and archived log files of the data source.

Compare Processing

Data changes are determined by comparing a "snapshot file" and the current original file. At the same time a new snapshot file can be created that will be used for the next compare.

Which file organizations are supported to capture the changed data?
Db2 Real-time/Near real-time, log processing, compare processing
IMS Real-time/Near real-time, log processing, compare processing
Adabas Real-time/Near real-time, log processing, compare processing
Adabas LUW Real-time/Near real-time, log processing, compare processing
CA-IDMS Real-time/Near real-time, log processing, compare processing
VSAM/CICS Real-time/Near real-time, log processing, compare processing
VSAM Real-time/Near real-time, log processing, compare processing
Sequential file Compare processing
CA-Datacom Log processing, compare processing
Db2/LUW Real-time/Near real-time, log processing, compare processing
Oracle Real-time/Near real-time, log processing, compare processing
MS SQL Server Real-time/Near real-time, log processing, compare processing
PostgreSQL Real-time/Near real-time, log processing, compare processing
Informix Real-time/Near real-time, log processing, compare processing
EXASOL Compare processing
TERADATA Compare processing
Are Logical Units of Work (LUW) supported?

Yes, tcVISION offers an LUW Manager for capturing methods "Real-time/Near real-time" and "Log processing". This manager can be used to make sure that all transaction changes are being applied to the target system in the correct sequence.

Which systems can I use as a target for my changed data?

The changed data can be applied to any target system. These systems can either reside on IBM mainframes, UNIX/Linux/Linux on System z or Windows platforms.

tcVISION offers a variety of options how the changed data can be propagated to the target system (ODBC, DRDA, Oracle-OCI, XML, FILE, Db2, VSAM, IMS, DL/I, Adabas, CA-Datacom, etc.).

Are special software components required for the individual target (e.g. SQL components) if changes are to be applied to mainframe files or databases?

No, changed data from Open System environments is applied in the file specific (e.g. VSAM) or database specific access method (e.g. IMS, Db2, Adabas, IDMS, etc.). No additional third-party software components are required.

Is it possible to maintain and process the changed data before it is implemented into the target system?

Yes, the changed data can be processed and maintained. tcVISION offers certain processing points (stages) to do it. The changed data is available in a processing specific format at any of these stages.

This guarantees a high degree of flexibility and assures that all processing requirements of your organization can be handled.

Processing rules can be stored in the tcVISION repository. These rules are automatically applied during the replication process.

Are any modifications to the operating system required during the installation, or is it necessary to IPL the system?

No, modifications to the operating system (z/OS, z/VSE) are not required.

The installation of the mainframe component is simple and straight forward. The distribution libraries must be loaded and a VSAM file must be allocated. The implementation of the DBMS Extensions follows standard and well documented procedures.

No IPL is required.

How does tcVISION determine which resources should be controlled to capture the changed data?

A graphical Windows application, the tcVISION control board, is used to create so-called "collector definitions" and "capture definitions". These definitions specify the resources that should be supervised to capture changed data. The control board provides intelligent wizards that help in the definition process.

How do I inform tcVISION about what the changed data looks like and which information in this data is of relevance for the propagation process?

tcVISION offers graphical import functions to import copybooks for various programming languages (COBOL, Assembler, PL/I, etc.).

The database definitions will be included in the analysis (PSB, DBD) during the import of metadata for an IMS or DL/I database.

In the case of Adabas and CA-Datacom the metadata will be automatically extracted from the corresponding dictionary. Metadata for CA-IDMS, including all navigation and connection parameters, are automatically extracted from SCHEMA definitions.

tcVISION analyzes the input data and checks for "Virtual Tables" (OCCURS, OCCURS DEPENDING ON, Adabas Periodic Groups and Multiple Fields) and offers different processing options during the import.

The structure information is stored in the tcVISION metadata repository. The tcVISION repository is the central database for all structure information and data formats used by the installation. The repository can be hosted by any relational database management system like Db2, Oracle or MS SQL Server, hence becoming an integral part of customer specific environments.

How can I prevent duplicate updates in a bidirectional environment which might happen when changes have been applied in the target system and are then captured and propagated to the originating system?

tcVISION comes with an integrated loopback prevention for a bidirectional data exchange. Individual criteria can be specified to detect and ignore changes that have already been applied.

Does tcVISION provide any tools to obtain and retrieve detailed information about current processes and processes that have already been completed?

tcVISION offers a comprehensive monitoring, logging and integrated alert notification.

During the processing optional performance data may be captured and saved into a relational database of your choice. The performance data can be analyzed and graphically displayed using a tcVISION web component.

Can I use tcVISION to perform an initial load of a new database?

Yes, tcVISION offers an intelligent BULK load component.

This component can be used to unload data from a mainframe or Open System data source and to load it into a target database either directly or by using a loader file.

Does tcVISION contain tools to design and create new databases based on the structures of the existing data structures?

Yes, the meta structure definitions from the tcVISION repository can be used to automatically create the SQL DML statements for the creation or the LOADing of the new target database.

The changed data and the data that should be bulk-loaded must be converted and normalized for the target system. Does that cause a severe performance impact on the mainframe?

With tcVISION practically any computer participating in the propagation process of the changed data can be used to perform the conversion and normalization, hence providing a workload balancing solution.

As an example, the captured data can be directly transferred in a highly compressed format to a UNIX machine that has enough free capacity to process the changed data and pass it through the various stages up to the creation of the change SQL-DML. This technique provides the most optimal utilization of available computer resources.