Attempt at speed optimization with sql-join

src/match.py

@@ -11,16 +11,22 @@ class StructureMatch:
     @staticmethod
     def from_db(db, colocation_id, structure):
         result = StructureMatch(colocation_id, structure)
-        for match_id in db.execute("SELECT mid_match_id FROM ColocationMatches WHERE mid_colocation_id=?", (colocation_id,)):
-            to_add = {}
+        prev_match_id = None
 
-            for component_id, word_lemma, word_text, word_msd, word_id in db.execute("""
-                SELECT component_id, word_lemma, word_text, word_msd, word_id 
-                FROM Matches WHERE match_id=?""", match_id):
+        stmt = """SELECT match_id, component_id, word_lemma, word_text, word_msd, word_id
+                  FROM ColocationMatches 
+                  JOIN Matches ON Matches.match_id=ColocationMatches.mid_match_id 
+                  WHERE mid_colocation_id=? 
+                  ORDER BY match_id"""
 
-                to_add[str(component_id)] = Word(word_lemma, word_msd, word_id, word_text, False)
+        for row in db.execute(stmt, (colocation_id,)): 
+            match_id, component_id, word_lemma, word_text, word_msd, word_id = row
 
-            result.matches.append(to_add)
+            if match_id != prev_match_id:
+                result.matches.append({})
+                prev_match_id = match_id
+
+            result.matches[-1][str(component_id)] = Word(word_lemma, word_msd, word_id, word_text, False)
         
         for component_id, text in db.execute("SELECT component_id, text FROM Representations WHERE colocation_id=?", (colocation_id,)):
             result.representations[str(component_id)] = text