Purge old witnesses

src/db.rs

@@ -694,6 +694,14 @@ impl DbAdapter {
                 params![min_height],
             )?;
             transaction.execute("DELETE FROM blocks WHERE height < ?1", params![min_height])?;
+            transaction.execute(
+                "DELETE FROM sapling_tree WHERE height < ?1",
+                params![min_height],
+            )?;
+            transaction.execute(
+                "DELETE FROM orchard_tree WHERE height < ?1",
+                params![min_height],
+            )?;
             transaction.commit()?;
         }
         log::debug!("-purge_old_witnesses");

src/scan.rs

@@ -207,8 +207,9 @@ async fn sync_async_inner<'a>(
             }
         }
 
-        let db = db_builder.build()?;
+        let mut db = db_builder.build()?;
         db.store_block_timestamp(last_height, &last_hash, last_timestamp)?;
+        db.purge_old_witnesses(last_height - 500)?;
         height = last_height;
         let cb = progress_callback.lock().await;
         cb(progress.clone());
@@ -219,6 +220,7 @@ async fn sync_async_inner<'a>(
     if get_tx {
         get_transaction_details(coin).await?;
     }
+
     Ok(())
 }