The JCC LogMiner Loader™ is a fast, powerful, flexible tool to reflect data changes from a source Rdb™ database to multiple targets. Targets can be other Rdb databases, Oracle® databases, a customer supplied API in XML format, or a Tuxedo application. The Loader has been exhaustively tested and tuned for all recent versions of these companion products.
The JCC LogMiner Loader has been used to replicate databases (or subsets of a database) for use at remote locations or for reporting databases with alternate tuning, to support database reorganization with downtime of minutes instead of hours, to regression test the performance of Rdb databases after physical tuning, to regression test an application, to audit changes to data, to rollup data from multiple source databases into a single target, and to provide data for alternate tools.
Once an organization has started to use the Loader, they quickly discover many additional uses for replicated data and often run multiple Loader sessions propagating data from a single source database. The licensing model for the Loader permits this at no incremental cost.
The JCC LogMiner Loader works with Oracle’s Rdb LogMiner to provide either off-line (static) or near real-time (continuous) support. Recent versions of the Loader use multi-threading and other advanced performance features to support the workloads implied by update-intensive databases. Monitoring and logging tools are available and are configurable and provide extensive support for performance analysis of Loader sessions and the architecture the Loader is used in. Additionally one style of monitoring conforms to the T4 performance measurement methodology supplied with version 7.3-2 of OpenVMS.
Advanced features provide for very flexible architectures. The Loader can be configured as an ETL tool in data warehouse projects to take changes to one row and direct them to several different tables in the target. Advanced filtering using SQL can restrict which rows are sent to the target. A Data Pump can be configured using SQL statements and a driver file to send selected rows to populate the target or correct issues that occur in the target because of other processing.
The Loader kit includes tools to assist the DBA and the Loader is driven by DBA input via a Control File and logical names. The Loader kit includes tools to assist the DBA in the creation of the control files and to monitor Loader performance while it is operating.
An Oracle Rdb database may be configured such that the database engine logs all changes made to a production database into a special file called the after image journal. The after image journal (or AIJ) contains records that indicate the status of each and every database object at the completion of a transaction. The Oracle Rdb LogMiner tool uses the after image journal to extract the final copies of data rows as they appear at the end of each transaction.
The LogMiner output represents the changes to the source database. The JCC LogMiner Loader enables a database administrator to apply the contents of the LogMiner output to one or more targets.
When run in continuous mode, the Loader coordinates the actions. In continuous mode, the LogMiner Loader updates the target in near real-time. (The results cannot be quite real-time since the information is not available from the LogMiner until the database commit.)
The DBA specifies the results required of the Loader through the Loader’s Control File. Loader options and features include:
Since Rdb environments generally strive for the utmost stability, many customers are running older versions of VMS. Release 2.2 of the Loader has been rigorously regression tested against a variety of OpenVMS versions including 7.3-x, 7.1 and 7.2. A single kit suffices for all of these versions.
The Loader kit has been linked with the SQL*net libraries for Oracle 8.1.7, 9.0 and 220.127.116.11 on VMS. Each of these interfaces has likewise been aggressively tested, though newer versions of the SQL*net libraries are not supported on earlier versions of VMS.
The Loader itself supports running a standard version and several varianted versions concurrently on the same system. This allows customers to install version 2.2 while continuing to run version 2.1 or 2.0 Loader sessions and even version 1.x sessions, although the version 2.21 kit includes sufficient fixes to merit an upgrade from earlier versions.
The JCC LogMiner Loader is a general-purpose tool and can assist a database administrator with a variety of functions. The following examples demonstrate a selection of the varied uses of the Loader:
For further information about the JCC LogMiner Loader, the current documentation is available at the JCC FTP site FTP.JCC.COM. The JCC LogMiner Loader supports either the static or continuous LogMiner.
The distribution kit may be obtained from the JCC FTP site via anonymous ftp.. This path also includes the documentation and release notes for version 2.2 together with training seminar materials and a presentation on the Loader.
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