Returns a specification to start this module under a supervisor.

See Supervisor.

Returns "index" when the first event of an event stream is indexed.

This is done so that a single index file is written that contains all the first events. If the stream name was returned instead, an index file would be created for each stream, and each index file would contain a single record id.

Examples

iex> event = %{
...>   "event_type" => "ClutchLaid", 
...>   "event_data" => %{"turtle_id" => "t1", "clutch_id" => "c1", "eggs" => 42}, 
...>   "event_tags" => ["turtle:t1", "clutch:c1"], 
...>   "stream_id" => "turtle_mating-1234",
...>   "stream_position" => 3
...> }
iex> Fact.EventStreamsIndexer.index_event(event, [])
nil

iex> event = %{
...>   "event_type" => "EggHatched", 
...>   "event_data" => %{"turtle_id" => "t2", "clutch_id" => "c1"}, 
...>   "event_tags" => ["turtle:t2", "clutch:c1"], 
...> }
iex> Fact.EventStreamsIndexer.index_event(event, [])
nil

iex> event = %{
...>   "event_type" => "DatabaseCreated", 
...>   "event_data" => %{"database_id" => "RVX27QR6PFDORJZF24C4DIICSQ"}, 
...>   "stream_id" => "__fact", 
...>   "stream_position" => 1
...> }
iex> Fact.EventStreamsIndexer.index_event(event, [])
"index"

Starts the indexer process.