Data divergence. Dbvisit 2.1

Dbvisit Replicate 2.1 is a powerful software solution for enabling real-time replication of Oracle databases. It uses redo log-based change data capture (CDC) technology to efficiently detect and replicate changes across Oracle and non-Oracle databases, including MySQL and SQL Server. This versatile tool allows for both one-way and two-way replication, facilitating various use cases like data migration, upgrades, data warehousing, and integration with other systems.

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DDC file /home/oracle/d112f/d112f-APPLY.ddc loaded.

Starting process APPLY...started

The replication on both servers has now been started and the data will be kept in sync.

Data divergence

Currently Dbvisit Replicate does not offer a tool to monitor or detect data divergence or to bring the data back in sync should data divergence occur.

However Dbvisit Replicate offers very robust and complete notification. This can be configured according to specific thresholds to ensure the replication does not fall behind too far where the data divergence becomes unmanageable.

In future Dbvisit Replicate may include a tool to detect and manage data divergence.

House keeping

Dbvisit Replicate offers automatic house keeping on the following files:

• Dbvisit Replicate plog files. These will get removed on source and target systems once they are no longer needed.

• Dbvisit Replicate log files. These are set managed to keep one backup file and a size limit of 100MB.

This is configurable through the parameters:

◦ LOG_FILE_SIZE

◦ LOG_FILE_COUNT

◦ LOG_FILE_DATE_ROTATE

Manual house keeping is required on the following files:

• Dbvisit Replicate trace files

• Dbvisit Replicate Cache files (see below)

Dbvisit Replicate Cache files

The Dbvisit Replicate executable (dbvrep) is a self contained executable and contains all the necessary required libraries for it to function. These libraries are extracted out of the executable and into the default temporary directory of the system at startup of dbvrep. Dbvisit Replicate will reuse these cache files the next time that it is started. This maybe noticeable in the startup time of dbvrep. If the cache already exists, the startup time is faster.

It maybe possible that there are several cache directories. This can happen if a new version of Dbvisit

Replicate is installed. The old cache directories can be removed, however when dbvrep is running, it is difficult to determine which is the current cache and which is the old cache. If the cache needs to be removed, then is preferable to shutdown dbvrep and then remove all cache files and then to restart dbvrep.

The cache files are in the OS default temp directory under a directory called par-username.

Except as specifically set out the Dbvisit license agreement, nothing in this Documentation constitutes a warranty as to the operation of the Dbvisit software.

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Key features

Real-time Oracle replication
Redolog-based change data capture (CDC)
One-way and two-way replication
Oracle, MySQL and SQL Server target databases
Heterogeneous configurations
ASM and RAC support
Efficient and low-overhead replication
Built-in conflict resolution
Comprehensive notification and alerting

Frequently asked questions

Dbvisit Replicate is software that replicates Oracle databases in real-time. It uses redo logs to track changes and apply them to target databases.

Dbvisit Replicate can replicate Oracle databases to other Oracle databases, MySQL databases, and SQL Server databases.

Dbvisit Replicate replicates both data changes (DML) and structure changes (DDL).

Dbvisit Replicate has built-in conflict resolution mechanisms that allow for different handling depending on the business requirements. You can choose to retry, pause, abort, discard, overwrite, call a PL/SQL routine, or prioritize newer or older changes.

No, Dbvisit Replicate does not require any changes to your database schema. It utilizes redo logs and does not rely on triggers, materialized views, or other programmatic changes.