Exasol Virtual Schemas are an abstraction layer that makes external data sources accessible in our data analytics platform through regular SQL commands. The contents of the external data sources are mapped to virtual tables which look like and can be queried as any regular Exasol table.
Regardless of whether that source is a relational database like ours, or it's like the structure of GitHub repositories, the interface that users see is always the same.
This means an user familiar with SQL will immediately feel at home when accessing remote data through Virtual Schemas.
Virtual Schemas can be also described in known terms as External Tables
or Foreign Data Wrapper (FDW)
.
The version of a Virtual Schema consists of two parts. The first part is the version of the Virtual Schema JDBC, the common basis that all JDBC-based Virtual Schemas share. Whereas the second part is the version of the Virtual Schema itself.
Thus the JAR filename of a Virtual Schema release complies with the following format:
virtual-schema-dist-<Virtual Schema JDBC Version>-<Virtual Schema Name>-<Virtual Schema Version>.jar
For example, the JAR filename of the Oracle Virtual Schema 2.3.0 release, which is based on the 10.0.1 version of Virtual Schema JDBC, is:
virtual-schema-dist-10.0.1-oracle-2.3.0.jar
The version of the Virtual Schema JDBC on which a Virtual Schema is based also tells you whether it is supported or discontinued, as shown in the following table:
Virtual Schema JDBC Version | Required Java Version | Lifecycle |
---|---|---|
11.x.x | 11 | supported, active development |
10.x.x | 11 | supported |
9.x.x | 11 | discontinued |
8.x.x | 11 | discontinued |
7.x.x | 11 | discontinued |
6.x.x | 11 | discontinued |
5.x.x | 11 | discontinued |
3.x.x | 11 | discontinued |
2.x.x | 9 | discontinued |
1.x.x | 8 | discontinued |
Please update your Virtual Schema to a supported version before writing tickets or contacting Exasol Support.
Exasol Version | Java Version Installed by Default in Language Container |
---|---|
8 | 11 |
7.1 | 11 |
7.0 | 11 |
6.2 | 11 |
6.1 | 9 |
6.0 | 8 |
We recommend updating the Exasol installation to at least 7.1.21 or newer for best results.
Please do not try to install language containers with lower Java versions on newer Exasol installations. This is untested.
Please contact the Exasol Support Team if you need help upgrading the language container.
The runtime dependencies are specified for each dialect in their own repository.
Please use the entry point
com.exasol.adapter.RequestDispatcher
in all your CREATE JAVA ADAPTER SCRIPT
statements. The old entry point was removed with the Version 2.0.0 of Exasol's Virtual Schema.
See List of Supported Dialects.
This is an open source project officially supported by Exasol. Please contact our support team if you have any questions.
NOTE: Please report dialect specific issues in the corresponding dialect repository (see the Supported Data Sources above)
Additional resources: