fix .env.example var and docs

QUICKSTART.md

@@ -42,8 +42,9 @@ POSTGRES_USER=postgres
 POSTGRES_PASSWORD=pgpassword
 POSTGRES_DATABASE=migrated_db
 
-BATCH_SIZE=10000
 LOG_LEVEL=INFO
+CONSOLIDATION_GROUP_LIMIT=40000
+PROGRESS_LOG_INTERVAL=10000
 ```
 
 ### 3. Creare PostgreSQL in Incus
@@ -224,8 +225,11 @@ python main.py setup --create-schema
 
 ### "Migration is slow"
 ```bash
-# Aumentare batch size in .env
-BATCH_SIZE=50000
+# Aumentare consolidation group limit in .env
+CONSOLIDATION_GROUP_LIMIT=80000
+
+# Oppure ridurre logging
+PROGRESS_LOG_INTERVAL=20000
 
 # Oppure ottimizzare MySQL
 mysql> FLUSH PRIVILEGES;