Add an index, document index use for Depot operations. Do you think this is worthwhile? We should really just about never see a non-indexed query during normal production use and one way to maintain that discipline is with a comment line like this.

git-svn-id: svn+ssh://src.earth.threerings.net/vilya/trunk@399 c613c5cb-e716-0410-b11b-feb51c14d237

src/java/com/threerings/parlor/rating/server/persist/RatingRecord.java

@@ -25,9 +25,12 @@ import com.samskivert.jdbc.depot.Key;
 import com.samskivert.jdbc.depot.PersistentRecord;
 import com.samskivert.jdbc.depot.annotation.Entity;
 import com.samskivert.jdbc.depot.annotation.Id;
+import com.samskivert.jdbc.depot.annotation.Index;
 import com.samskivert.jdbc.depot.expression.ColumnExp;
 
-@Entity
+@Entity(indices={
+    @Index(name="ixPlayerId", columns={ RatingRecord.PLAYER_ID })
+})
 public class RatingRecord extends PersistentRecord
 {
     // AUTO-GENERATED: FIELDS START
@@ -60,19 +63,19 @@ public class RatingRecord extends PersistentRecord
         new ColumnExp(RatingRecord.class, EXPERIENCE);
     // AUTO-GENERATED: FIELDS END
 
-    public static final int SCHEMA_VERSION = 1;
+    public static final int SCHEMA_VERSION = 2;
 
     /** The identifier of the game we're rating for. */
     @Id
     public int gameId;
 
-    /** The identifier of the player we're rating. */ 
+    /** The identifier of the player we're rating. */
     @Id
     public int playerId;
-    
+
     /** The player's current rating. */
     public int rating;
-    
+
     /** The number of times the player has played this game. */
     public int experience;
 
@@ -83,14 +86,14 @@ public class RatingRecord extends PersistentRecord
     {
         super();
     }
-    
+
     /**
      * A constructor that populates all our fields.
      */
     public RatingRecord (int gameId, int playerId, int rating, int experience)
     {
         super();
-        
+
         this.gameId = gameId;
         this.playerId = playerId;
         this.rating = rating;

src/java/com/threerings/parlor/rating/server/persist/RatingRepository.java

@@ -54,15 +54,16 @@ public class RatingRepository extends DepotRepository
     public RatingRecord getRating (int gameId, int playerId)
         throws PersistenceException
     {
-        return load(RatingRecord.class,
-                    RatingRecord.GAME_ID, gameId,
-                    RatingRecord.PLAYER_ID, playerId);
+        // INDEX: Full primary key.
+        return load(RatingRecord.class, RatingRecord.getKey(gameId, playerId));
     }
 
     /**
      * Fetch the ratings registered for any of the given players for the given game and return
      * them as a list of {@link RatingRecord} objects. The size of this list is no less than zero
      * and no greater than the number of given players.
+     *
+     * INDEXING: Uses primary key.
      */
     public List<RatingRecord> getRatings (int gameId, Integer... players)
         throws PersistenceException
@@ -70,17 +71,19 @@ public class RatingRepository extends DepotRepository
         if (players.length == 0) {
             return Collections.emptyList();
         }
+        // INDEX: Full primary key.
         return findAll(RatingRecord.class,
                        new Where(new And(new Equals(RatingRecord.GAME_ID_C, gameId),
                                          new In(RatingRecord.PLAYER_ID_C, players))));
     }
 
     /**
-     * Fetch and return all the registered {@link RatingRecord} rows for the given player. 
+     * Fetch and return all the registered {@link RatingRecord} rows for the given player.
      */
     public List<RatingRecord> getRatings (int playerId)
         throws PersistenceException
     {
+        // INDEX: ixPlayerId
         return findAll(RatingRecord.class, new Where(RatingRecord.PLAYER_ID_C, playerId));
     }