If the database contained many CLOB or BLOB values, then closing a connection was very slow.

h2/src/main/org/h2/store/LobStorage.java

@@ -94,6 +94,7 @@ public class LobStorage {
             // stat.execute("SET UNDO_LOG 0");
             // stat.execute("SET REDO_LOG_BINARY 0");
             stat.execute("CREATE TABLE IF NOT EXISTS " + LOBS + "(ID BIGINT PRIMARY KEY, BYTE_COUNT BIGINT, TABLE INT) HIDDEN");
+            stat.execute("CREATE INDEX IF NOT EXISTS INFORMATION_SCHEMA.INDEX_LOB_TABLE ON " + LOBS + "(TABLE)");
             stat.execute("CREATE TABLE IF NOT EXISTS " + LOB_MAP + "(LOB BIGINT, SEQ INT, HASH INT, BLOCK BIGINT, PRIMARY KEY(LOB, SEQ)) HIDDEN");
             stat.execute("CREATE INDEX IF NOT EXISTS INFORMATION_SCHEMA.INDEX_LOB_MAP_DATA_LOB ON " + LOB_MAP + "(BLOCK, LOB)");
             stat.execute("CREATE TABLE IF NOT EXISTS " + LOB_DATA + "(BLOCK BIGINT PRIMARY KEY, COMPRESSED INT, DATA BINARY) HIDDEN");