diff --git a/README.md b/README.md
index 1b0df6d..d0690e1 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,14 @@
 # ShopMC
 MC Shop
-
+## Logging
+This plugin records shop transactions either to a local YAML file or to a
+MySQL database. Logging and lookups run asynchronously to avoid blocking the
+server thread. When using MySQL, the table is created with indexes on the
+player and timestamp columns to keep queries fast.
 ## Commands
 - `/shop [buy|price|search|admin]` – Buy from the server shop or open GUI
 - `/sell <material> <qty>` – Sell to the server shop
 - `/sellall` – Sell all sellable items in your inventory
 - `/shoplog [player] [limit]` – View transaction log
 - `/weeklyshop` – Show weekly shop items
+
diff --git a/src/main/java/com/yourorg/servershop/logging/SQLLogStorage.java b/src/main/java/com/yourorg/servershop/logging/SQLLogStorage.java
index 7d35134..43f766b 100644
--- a/src/main/java/com/yourorg/servershop/logging/SQLLogStorage.java
+++ b/src/main/java/com/yourorg/servershop/logging/SQLLogStorage.java
@@ -33,6 +33,8 @@ private void init() throws Exception {
                     "amount DOUBLE NOT NULL," +
                     "INDEX idx_player_time (player, time_ms)" +
                     ") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4");
+            // Ensure efficient global queries by indexing by time as well
+            st.executeUpdate("CREATE INDEX IF NOT EXISTS idx_time_ms ON servershop_transactions(time_ms)");
         }
     }