edk2toollib.database.edk2_db: Add env index to large tables

Most queries rely on a specific env value when generating results;
this commit adds an index on the env column for the junction and
instanced_inf tables as they get extremely large and index's here
will improve performance when filtering on a specific env value.

Author: Javagedes

edk2toollib/database/edk2_db.py

@@ -26,6 +26,11 @@
 )
 """
 
+CREATE_JUNCTION_INDEX = """
+CREATE INDEX IF NOT EXISTS junction_idx
+ON junction (env);
+"""
+
 class Edk2DB:
     """A SQLite3 database manager for a EDKII workspace.
 
@@ -97,6 +102,7 @@ def parse(self, env: dict) -> None:
             not exist, and a row is added for each call of this command.
         """
         self.connection.execute(CREATE_JUNCTION_TABLE)
+        self.connection.execute(CREATE_JUNCTION_INDEX)
         id = str(uuid.uuid4().hex)
 
         # Create all tables