diff --git a/api/__init__.py b/api/__init__.py
index 39de2f4..68ff11a 100644
--- a/api/__init__.py
+++ b/api/__init__.py
@@ -9,7 +9,7 @@ from .operation import ChangeSet
 from .operation import get_current_operation
 from .operation import execute_undo, execute_redo
 from .operation import have_snapshot, take_snapshot, pick_snapshot
-from .operation import pick_operation, sync_with_server
+from .operation import pick_operation, sync_with_server, get_restore_operation
 
 from .command import execute_batch_command, execute_batch_commands
 
diff --git a/api/operation.py b/api/operation.py
index b2f6ca1..44cf20e 100644
--- a/api/operation.py
+++ b/api/operation.py
@@ -307,3 +307,7 @@ def sync_with_server(name: str, operation: int) -> ChangeSet:
             index -= 1
 
     return change.compress()
+
+
+def get_restore_operation(name: str) -> int:
+    return read(name, f'select * from restore_operation')['id']
diff --git a/api/parser.py b/api/parser.py
index bca8470..f3835f5 100644
--- a/api/parser.py
+++ b/api/parser.py
@@ -221,7 +221,9 @@ def read_inp(project: str, inp: str):
     create_project(project)
     open_project(project)
 
-    execute_batch_command(project, _read_inp(inp))
+    execute_batch_commands(project, _read_inp(inp))
+    op = get_current_operation(project)
+    write(project, f'update restore_operation set id = {op}')
 
 
 def dump_inp(project: str, inp: str):
diff --git a/build_db.py b/build_db.py
index 550a692..997f096 100644
--- a/build_db.py
+++ b/build_db.py
@@ -4,7 +4,7 @@ files = [
     'bwsn',
     'exnet',
     'fengxian',
-    #'jbh', # too big sql to compress
+    'jbh',
     'nanjing',
     'net3',
     'zj',
@@ -19,7 +19,5 @@ def db2inp():
         dump_inp(file, f'db_{file}.inp')
 
 if __name__ == '__main__':
-    #inp2db()
-    #db2inp()
-    print(run_project('net3'))
-    pass
\ No newline at end of file
+    inp2db()
+    db2inp()
diff --git a/script/sql/create/operation.sql b/script/sql/create/operation.sql
index 05320e2..dc4f220 100644
--- a/script/sql/create/operation.sql
+++ b/script/sql/create/operation.sql
@@ -1,6 +1,6 @@
 create table operation
 (
-  id serial primary key
+  id bigserial primary key
 , redo text not null
 , undo text not null
 , parent integer references operation(id) on delete cascade
@@ -13,13 +13,20 @@ insert into operation (id, redo, undo, redo_cs, undo_cs) values (0, '', '', '',
 
 create table current_operation
 (
-  id integer primary key references operation(id) -- must update before delete
+  id bigint primary key references operation(id) -- must update before delete
 );
 
 insert into current_operation (id) values (0);
 
 create table snapshot_operation
 (
-  id integer primary key references operation(id) on delete cascade
+  id bigint primary key references operation(id) on delete cascade
 , tag text not null unique
 );
+
+create table restore_operation
+(
+  id bigint primary key references operation(id) -- set after reading inp
+);
+
+insert into restore_operation (id) values (0);
diff --git a/script/sql/drop/operation.sql b/script/sql/drop/operation.sql
index 344215a..06a7765 100644
--- a/script/sql/drop/operation.sql
+++ b/script/sql/drop/operation.sql
@@ -1,4 +1,4 @@
-drop table if exists transaction_operation;
+drop table if exists restore_operation;
 
 drop table if exists snapshot_operation;
 
diff --git a/tjnetwork.py b/tjnetwork.py
index 91c4dc9..f5bc86c 100644
--- a/tjnetwork.py
+++ b/tjnetwork.py
@@ -179,6 +179,9 @@ def execute_batch_command(name: str, cs: ChangeSet) -> ChangeSet:
 def execute_batch_commands(name: str, cs: ChangeSet) -> ChangeSet:
     return api.execute_batch_commands(name, cs)
 
+def get_restore_operation(name: str) -> int:
+    return api.get_restore_operation(name)
+
 
 ############################################################
 # type