composite index for channel/seq_id

spacetimedb/src/tables.rs

@@ -180,7 +180,7 @@ pub struct Reaction {
     pub custom_emoji_id: Option<u64>,
 }
 
-#[spacetimedb::table(accessor = message)]
+#[spacetimedb::table(accessor = message, index(accessor = channel_seq, btree(columns = [channel_id, seq_id])))]
 #[derive(Clone)]
 pub struct Message {
     #[primary_key]

spacetimedb/src/views.rs

@@ -81,16 +81,14 @@ pub fn visible_recent_activity(ctx: &ViewContext) -> Vec<Message> {
         let limit = get_recent_message_limit_read_only(&ctx.db);
         let min_seq = if last_seq_id > limit { last_seq_id - (limit - 1) } else { 1 };
 
-        for msg in ctx.db.message().channel_id().filter(access.channel_id) {
-            if msg.seq_id >= min_seq {
-                results.push(msg.clone());
-            }
+        // HIGH PERFORMANCE: Uses composite index range scan
+        for msg in ctx.db.message().channel_seq().filter((access.channel_id, min_seq..)) {
+            results.push(msg.clone());
         }
     }
 
     results
 }
-
 #[spacetimedb::view(accessor = visible_servers, public)]
 pub fn visible_servers(ctx: &ViewContext) -> Vec<Server> {
     let identity = ctx.sender();