The server has built-in support for different databases. You can query the available databases by viewing the expected values for the `db` configuration option. The following table lists the supported databases and their tested versions.
By default, the server uses the `dev-file` database. This is the default database that the server will use to persist data and
only exists for development use-cases. The `dev-file` database is not suitable for production use-cases, and must be replaced before deploying to production.
. Download the `ojdbc11` and `orai18n` JAR files from one of the following sources:
.. *Zipped JDBC driver and Companion Jars* version ${properties["oracle-jdbc.version"]} from the https://www.oracle.com/database/technologies/appdev/jdbc-downloads.html[Oracle driver download page].
.. Maven Central via `link:++https://repo1.maven.org/maven2/com/oracle/database/jdbc/ojdbc11/${properties["oracle-jdbc.version"]}/ojdbc11-${properties["oracle-jdbc.version"]}.jar++[ojdbc11]` and `link:++https://repo1.maven.org/maven2/com/oracle/database/nls/orai18n/${properties["oracle-jdbc.version"]}/orai18n-${properties["oracle-jdbc.version"]}.jar++[orai18n]`.
.. Installation media recommended by the database vendor for the specific database in use.
. When running containers: Build a custom {project_name} image and add the JARs in the `providers` folder. When building a custom image for the Operator, those images need to be optimized images with all build-time options of {project_name} set.
A minimal Containerfile to build an image which can be used with the {project_name} Operator and includes Oracle Database JDBC drivers downloaded from Maven Central looks like the following:
. Download the `mssql-jdbc` JAR file from one of the following sources:
.. Download a version from the https://learn.microsoft.com/en-us/sql/connect/jdbc/download-microsoft-jdbc-driver-for-sql-server[Microsoft JDBC Driver for SQL Server page].
.. Maven Central via `link:++https://repo1.maven.org/maven2/com/microsoft/sqlserver/mssql-jdbc/${properties["mssql-jdbc.version"]}/mssql-jdbc-${properties["mssql-jdbc.version"]}.jar++[mssql-jdbc]`.
.. Installation media recommended by the database vendor for the specific database in use.
. When running containers: Build a custom {project_name} image and add the JARs in the `providers` folder. When building a custom image for the {project_name} Operator, those images need to be optimized images with all build-time options of {project_name} set.
A minimal Containerfile to build an image which can be used with the {project_name} Operator and includes Microsoft SQL Server JDBC drivers downloaded from Maven Central looks like the following:
For each supported database, the server provides some opinionated defaults to simplify database configuration. You complete the configuration by providing some key settings such as the database host and credentials.
The server uses JDBC as the underlying technology to communicate with the database. If the default connection settings are insufficient, you can specify a JDBC URL using the `db-url` configuration option.
Be aware that you need to escape characters when invoking commands containing special shell characters such as `;` using the CLI, so you might want to set it in the configuration file instead.
Unicode support for all fields depends on whether the database allows VARCHAR and CHAR fields to use the Unicode character set.
* If these fields can be set, Unicode is likely to work, usually at the expense of field length.
* If the database only supports Unicode in the NVARCHAR and NCHAR fields, Unicode support for all text fields is unlikely to work because the server schema uses VARCHAR and CHAR fields extensively.
Otherwise, characters are limited to those contained in database encoding, which is often 8-bit. However, for some database systems, you can enable UTF-8 encoding of Unicode characters and use the full Unicode character set in all text fields. For a given database, this choice might result in a shorter maximum string length than the maximum string length supported by 8-bit encodings.
Unicode characters are supported in an Oracle database if the database was created with Unicode support in the VARCHAR and CHAR fields. For example, you configured AL32UTF8 as the database character set. In this case, the JDBC driver requires no special settings.
If the database was not created with Unicode support, you need to configure the JDBC driver to support Unicode characters in the special fields. You configure two properties. Note that you can configure these properties as system properties or as connection properties.
Unicode characters are supported in a MySQL database if the database was created with Unicode support in the VARCHAR and CHAR fields when using the CREATE DATABASE command.
Note that the utf8mb4 character set is not supported due to different storage requirements for the utf8 character set. See MySQL documentation for details. In that situation, the length restriction on non-special fields does not apply because columns are created to accommodate the number of characters, not bytes. If the database default character set does not allow Unicode storage, only the special fields allow storing Unicode values.
Unicode is supported for a PostgreSQL database when the database character set is UTF8. Unicode characters can be used in any field with no reduction of field length for non-special fields. The JDBC driver requires no special settings. The character set is determined when the PostgreSQL database is created.
When using Amazon Aurora PostgreSQL, the https://github.com/awslabs/aws-advanced-jdbc-wrapper[Amazon Web Services JDBC Driver] offers additional features like transfer of database connections when a writer instance changes in a Multi-AZ setup.
This driver is not part of the distribution and needs to be installed before it can be used.
To install this driver, apply the following steps:
. When running the unzipped distribution: Download the JAR file from the https://github.com/awslabs/aws-advanced-jdbc-wrapper/releases/[Amazon Web Services JDBC Driver releases page] and place it in {project_name}'s `providers` folder.
. When running containers: Build a custom {project_name} image and add the JAR in the `providers` folder.
See the <@links.server id="containers" /> {section} for details on how to build optimized images, and the <@links.operator id="customizing-keycloak" /> {section} on how to run optimized and non-optimized images with the {project_name} Operator.
. Configure {project_name} to run with the following parameters:
`db-url`:: Insert `aws-wrapper` to the regular PostgreSQL JDBC URL resulting in a URL like `+jdbc:aws-wrapper:postgresql://...+`.
`db-driver`:: Set to `software.amazon.jdbc.Driver` to use the AWS JDBC wrapper.
Beginning with MySQL 8.0.30, MySQL supports generated invisible primary keys for any InnoDB table that is created without an explicit primary key (more information https://dev.mysql.com/doc/refman/8.0/en/create-table-gipks.html[here]).
If this feature is enabled, the database schema initialization and also migrations will fail with the error message `Multiple primary key defined (1068)`.
You then need to disable it by setting the parameter `sql_generate_invisible_primary_key` to `OFF` in your MySQL server configuration before installing or upgrading {project_name}.
Because cluster nodes can boot concurrently, they take extra time for database actions. For example, a booting server instance may perform some database migration, importing, or first time initializations. A database lock prevents start actions from conflicting with each other when cluster nodes boot up concurrently.
The maximum timeout for this lock is 900 seconds. If a node waits on this lock for more than the timeout, the boot fails. The need to change the default value is unlikely, but you can change it by entering this command:
