sqldb/sqlc: add index on graph_channels(version, id)

Author: ellemouton

sqldb/sqlc/migrations/000007_graph.down.sql

@@ -9,6 +9,7 @@ DROP INDEX IF EXISTS graph_channels_node_id_1_idx;
 DROP INDEX IF EXISTS graph_channels_node_id_2_idx;
 DROP INDEX IF EXISTS graph_channels_unique;
 DROP INDEX IF EXISTS graph_channels_version_outpoint_idx;
+DROP INDEX IF EXISTS graph_channels_version_id_idx;
 DROP INDEX IF EXISTS graph_channel_features_unique;
 DROP INDEX IF EXISTS graph_channel_extra_types_unique;
 DROP INDEX IF EXISTS graph_channel_policies_unique;

sqldb/sqlc/migrations/000007_graph.up.sql

@@ -173,6 +173,7 @@ CREATE TABLE IF NOT EXISTS graph_channels (
 -- indexes on the node_id_1 and node_id_2 columns.
 CREATE INDEX IF NOT EXISTS graph_channels_node_id_1_idx ON graph_channels(node_id_1);
 CREATE INDEX IF NOT EXISTS graph_channels_node_id_2_idx ON graph_channels(node_id_2);
+CREATE INDEX graph_channels_version_id_idx ON graph_channels(version, id);
 
 -- A channel (identified by a short channel id) can only have one active
 -- channel announcement per protocol version. We also order the index by