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Experimental Features

Autor: Adam Leszczyński <[email protected]>, version: 1.6.1, date: 2024-06-01

This document describes the experimental features of OpenLogReplicator. By default, all experimental features are disabled and must be enabled in the configuration file.

Table of Contents

Binary XMLType Support

Configuration Parameters

To enable binary XMLType support, set the following parameters in the configuration file:

"flags":65536

Feature Description

The Oracle database uses a special binary format to store XMLType data. Let’s consider the following SQL commands:

CREATE TABLE USR1.ADAM1 (
  A NUMBER(3),
  B XMLTYPE
);

CREATE TABLE USR1.ADAM2 (
   A NUMBER,
   B XMLTYPE
) XMLTYPE B STORE AS CLOB;

In the example above USR1.ADAM1 table stores XMLType data in a binary format, while USR1.ADAM2 stores it in a CLOB. The binary format is more efficient, but it is not human-readable and requires special tools to decode it. The CLOB format is human-readable, but it is less efficient in terms of storage and optimization related size of XML data.

Note
 Storing in CLOB format causes the data to be stored in the exact same format as it was inserted. This means that the data is not optimized and may contain unnecessary whitespaces, line breaks, etc. Storing in binary format causes the data to be optimized, which means that it may be stored in a different format than it was inserted.

To decode binary XMLType, OpenLogReplicator uses the data stored in the XDB schema dictionaries. This might cause the dictionaries to grow significantly, which may lead to performance issues.

Important
 The feature is in an experimental state, meaning that it may not work correctly in all cases. Please report any issues to the project’s GitHub page. This will help to improve the feature and make it more stable.

Limitations

Binary XMLType support is available for all supported database versions except version 23c.