Add dox for SparkSQL [ci skip]

docs/administration-guide/01-managing-databases.md

@@ -24,6 +24,7 @@ Now you’ll see a list of your databases. To connect another database to Metaba
 * [Vertica](databases/vertica.md)
 * Presto
 * Google Analytics
+* [SparkSQL](databases/spark.md)
 
 To add a database, you'll need its connection information.
 

docs/administration-guide/databases/spark.md

@@ -0,0 +1,50 @@
+## Working with SparkSQL in Metabase
+
+Starting in v0.29.0, Metabase provides a driver for connecting to SparkSQL databases. Under the hood, Metabase uses SparkSQL's
+JDBC driver and other dependencies; due to the sheer size of this dependency, we can't include it as part of Metabase. Luckily, downloading it yourself
+ and making it available to Metabase is straightforward and only takes a few minutes.
+
+### Downloading the SparkSQL JDBC Driver JAR
+
+You can download the required dependencies [here](https://s3.amazonaws.com/sparksql-deps/metabase-sparksql-deps-1.2.1.spark2-standalone.jar).
+
+### Adding the SparkSQL JDBC Driver JAR to the Metabase Plugins Directory
+
+Metabase will automatically make the SparkSQL driver available if it finds the SparkSQL dependencies JAR in the Metabase plugins
+directory when it starts up. All you need to do is create the directory, move the JAR you just downloaded into it, and restart
+Metabase.
+
+By default, the plugins directory is called `plugins`, and lives in the same directory as the Metabase JAR.
+
+For example, if you're running Metabase from a directory called `/app/`, you should move the SparkSQL dependencies JAR to
+`/app/plugins/`:
+
+```bash
+# example directory structure for running Metabase with SparkSQL support
+/app/metabase.jar
+/app/plugins/metabase-sparksql-deps-1.2.1.spark2-standalone.jar
+```
+
+If you're running Metabase from the Mac App, the plugins directory defaults to `~/Library/Application Support/Metabase/Plugins/`:
+
+```bash
+# example directory structure for running Metabase Mac App with SparkSQL support
+/Users/camsaul/Library/Application Support/Metabase/Plugins/metabase-sparksql-deps-1.2.1.spark2-standalone.jar
+```
+
+Finally, you can choose a custom plugins directory if the default doesn't suit your needs by setting the environment variable
+`MB_PLUGINS_DIR`.
+
+
+### Enabling Plugins on Java 9
+
+Java 9 disables dynamically adding JARs to the Java classpath by default for security reasons. For the time being, we recommend you
+run Metabase with Java 8 when using the SparkSQL driver.
+
+You may be able to get Java 9 to work by passing an extra JVM option:
+
+```bash
+java --add-opens=java.base/java.net=ALL-UNNAMED -jar metabase.jar
+```
+
+The default Docker images already include this option.