Expansion is configured using command line flags or environment variables. To see the list of command line flags that are available (and their default values) for your version of Horizon, run:
When you run the command above, you'll see that Horizon defines a large number of flags; however, only three are required:
--db-urlspecifies the Horizon database, and its value should be a valid PostgreSQL Connection URI.
--bantu-core-db-urlspecifies a Stellar Core database which will be used to load data from the Stellar ledger. Finally,
--bantu-core-urlspecifies the HTTP control port for an instance of Stellar Core. This URL should be associated with the Stellar Core server that is writing to the database at
Additionally, if you are running a single Expansion instance you should start ingestion using the following flags:
Before running the Expansion server, you must first prepare the Horizon database. This database will be used for all of the information produced by Horizon, notably historical information about successful transactions that have occurred on the stellar network.
To prepare a database for Horizon's use, you must first ensure the database is blank. It's easiest to simply create a new database on your postgres server specifically for Horizon's use. Next you must install the schema by running
horizon db init. Remember to use the appropriate command line flags or environment variables to configure Horizon as explained in Configuring . This command will log any errors that occur.
It is recommended to set
random_page_cost=1in Postgres configuration if you are using SSD storage. With this setting Query Planner will make a better use of indexes, expecially for
JOINqueries. We've noticed a huge speed improvement for some queries.