Document DataSource implementations supported by DataSourceBuilder

Closes gh-25333

Author: snicoll

spring-boot-project/spring-boot-docs/src/docs/asciidoc/spring-boot-features.adoc

@@ -4085,22 +4085,11 @@ Disabling the database's automatic shutdown lets Spring Boot control when the da
 [[boot-features-connect-to-production-database]]
 ==== Connection to a Production Database
 Production database connections can also be auto-configured by using a pooling `DataSource`.
-Spring Boot uses the following algorithm for choosing a specific implementation:
-
-. We prefer https://github.com/brettwooldridge/HikariCP[HikariCP] for its performance and concurrency.
-  If HikariCP is available, we always choose it.
-. Otherwise, if the Tomcat pooling `DataSource` is available, we use it.
-. Otherwise, if https://commons.apache.org/proper/commons-dbcp/[Commons DBCP2] is available, we use it.
-. If none of HikariCP, Tomcat, and DBCP2 are available and if Oracle UCP is available, we use it.
 
-If you use the `spring-boot-starter-jdbc` or `spring-boot-starter-data-jpa` "`starters`", you automatically get a dependency to `HikariCP`.
 
-NOTE: You can bypass that algorithm completely and specify the connection pool to use by setting the configprop:spring.datasource.type[] property.
-This is especially important if you run your application in a Tomcat container, as `tomcat-jdbc` is provided by default.
-
-TIP: Additional connection pools can always be configured manually.
-If you define your own `DataSource` bean, auto-configuration does not occur.
 
+[[boot-features-connect-to-production-database-configuration]]
+==== DataSource Configuration
 DataSource configuration is controlled by external configuration properties in `+spring.datasource.*+`.
 For example, you might declare the following section in `application.properties`:
 
@@ -4119,12 +4108,11 @@ Otherwise, Spring Boot tries to auto-configure an embedded database.
 TIP: Spring Boot can deduce the JDBC driver class for most databases from the URL.
 If you need to specify a specific class, you can use the configprop:spring.datasource.driver-class-name[] property.
 
-
 NOTE: For a pooling `DataSource` to be created, we need to be able to verify that a valid `Driver` class is available, so we check for that before doing anything.
 In other words, if you set `spring.datasource.driver-class-name=com.mysql.jdbc.Driver`, then that class has to be loadable.
 
 See {spring-boot-autoconfigure-module-code}/jdbc/DataSourceProperties.java[`DataSourceProperties`] for more of the supported options.
-These are the standard options that work regardless of the actual implementation.
+These are the standard options that work regardless of <<boot-features-connect-to-production-database-connection-pool, the actual implementation>>.
 It is also possible to fine-tune implementation-specific settings by using their respective prefix (`+spring.datasource.hikari.*+`, `+spring.datasource.tomcat.*+`, `+spring.datasource.dbcp2.*+`, and `+spring.datasource.oracleucp.*+`).
 Refer to the documentation of the connection pool implementation you are using for more details.
 
@@ -4144,6 +4132,35 @@ This will set the pool to wait 10000 ms before throwing an exception if no conne
 
 
 
+[[boot-features-connect-to-production-database-connection-pool]]
+==== Supported Connection Pools
+Spring Boot uses the following algorithm for choosing a specific implementation:
+
+. We prefer https://github.com/brettwooldridge/HikariCP[HikariCP] for its performance and concurrency.
+If HikariCP is available, we always choose it.
+. Otherwise, if the Tomcat pooling `DataSource` is available, we use it.
+. Otherwise, if https://commons.apache.org/proper/commons-dbcp/[Commons DBCP2] is available, we use it.
+. If none of HikariCP, Tomcat, and DBCP2 are available and if Oracle UCP is available, we use it.
+
+NOTE: If you use the `spring-boot-starter-jdbc` or `spring-boot-starter-data-jpa` "`starters`", you automatically get a dependency to `HikariCP`.
+
+You can bypass that algorithm completely and specify the connection pool to use by setting the configprop:spring.datasource.type[] property.
+This is especially important if you run your application in a Tomcat container, as `tomcat-jdbc` is provided by default.
+
+Additional connection pools can always be configured manually, using `DataSourceBuilder`.
+If you define your own `DataSource` bean, auto-configuration does not occur.
+The following connection pools are supported by `DataSourceBuilder`:
+
+* HikariCP
+* Tomcat pooling `Datasource`
+* Commons DBCP2
+* Orale UCP & `OracleDataSource`
+* Spring Framework's `SimpleDriverDataSource`
+* H2 `JdbcDataSource`
+* PostgreSQL `PGSimpleDataSource`
+
+
+
 [[boot-features-connecting-to-a-jndi-datasource]]
 ==== Connection to a JNDI DataSource
 If you deploy your Spring Boot application to an Application Server, you might want to configure and manage your DataSource by using your Application Server's built-in features and access it by using JNDI.