redo log

Oracle database log-based CDC on Raspberry PI

The task here is just to run native replication solution directly on Raspberry PI hardware. No emulators, no workarounds, no cheating. Let’s find out what is the redo log processing speed. The key to this approach is using OpenLogReplicator as CDC engine and it’s offline mode. With this mode you can read redo logs without …

Oracle database log-based CDC on Raspberry PI Read More »

Supplemental logging – how much space does it require?

Oracle at some point of decided that users might want to replicate the changes from the database to other targets. What they noticed, that the architecture of the database did not allow easy replication since the redo log did not contain information that would allow to identify the exact row, that has been modified. The …

Supplemental logging – how much space does it require? Read More »

Oracle redo log format community documentation

The format is proprietary and there is no public official document which would describe the structure. Here is a brief summary of various sources which are publicly available. One might think that there is very little information available, but that’s not true. This is a list I have made in the past when I was …

Oracle redo log format community documentation Read More »

OpenLogReplicator – logdump functionality

A side product of OpenLogReplicator is the ability to create logs which are in a very simular form as the logdump command from Oracle database. To create such dump you need to configure parameter in the OpenLogReplicator CFG file. There are 2 allowed values: create classic ‘logdump’ output create classic ‘logdump’ output enhanced with interpretation …

OpenLogReplicator – logdump functionality Read More »

OpenLogReplicator – Delete row piece (OP 11.3) and Truncate table (OP 24.1)

The OpenLogReplicator has been a new release 0.0.8 with new functionality: Added rowid field to JSON (Kafka target) Support for OP code 11.3 – Delete Row Piece Support for OP code 24.1 – DDL: Truncate table (only Kafka target) Here is an example of usage. Let’s create a table: CREATE TABLE SYSTEM.ADAM3( A NUMERIC ); …

OpenLogReplicator – Delete row piece (OP 11.3) and Truncate table (OP 24.1) Read More »

OpenLogReplicator – Insert multiple rows (OP 11.11)

The OpenLogReplicator has been extended to support also OP code 11.11 – Insert Multiple Rows. This type of redo record is used when an INSERT is used with a set of rows to be inserted. For example with INSERT … SELECT … . Here is an example of usage. Let’s create a table: CREATE TABLE …

OpenLogReplicator – Insert multiple rows (OP 11.11) Read More »

OpenLogReplicator – CDC replication from Oracle to Redis

OpenLogReplicator – the first open-source transaction replicator (CDC) to Kafka now supports also Redis as a target. Check the new released version 0.0.3 (compiled for x86_64). It requires additionally the hiredis library To run: Testing with Redis: Redis: All transactions are replicated with consistency (MULTI/EXEC). Enjoy!

OpenLogReplicator – first log-based open source Oracle to Kafka CDC replication

I have figured out that writing about somebody else’s software is boring. Why not create your own. So here it is: All code GPL v.3 Just C++ code – absolutely no Java/Python or any other interpreted language Purely reading Oracle Redo Log from disk – zero additional load to the database instance High performance architecture …

OpenLogReplicator – first log-based open source Oracle to Kafka CDC replication Read More »

Preventing archive log deletion before being processed by Oracle GoldenGate

Oracle GoldenGate just like Oracle Streams has a mechanism of preventing archive logs from being deleted before they are processed. This mechanism is supported both in Classic and Integrated Extract mode. Although the latter one offers more functionality and control. This article brings in dept analysis what is happening in the database.

Oracle GoldenGate: What is ADD TRANDATA really doing?

In the process of data replication using Oracle GoldenGate the first step is assuring that all the needed information has been written to the database redo log. By default the database does not write all the information that might be needed by the replication process. That’s why some additional supplemental logging is needed. According to …

Oracle GoldenGate: What is ADD TRANDATA really doing? Read More »