Merge pull request ARCH-commons#45 from njgraham/backup_cdm_4407

Backup CDM tables to a different schema (#4407)

Oracle/backup_cdm.py

@@ -12,53 +12,58 @@
 
 
 def main(get_cursor):
-    cursor = get_cursor()
+    cursor, backup_schema = get_cursor()
 
     for table in CDM3_TABLES:
-        if has_rows(cursor, table):
-            drop_triggers(cursor, table)
-            drop(cursor, table + '_BAK')
-            rename(cursor, table, table + '_BAK')
-
-
-def drop_triggers(cursor, table):
-    cursor.execute("""select trigger_name
-                   from user_triggers
-                   where table_name = '%(table)s'""" %
-                   dict(table=table))
-
-    for res in cursor.fetchall():
-        cursor.execute('drop trigger %(trigger)s' % dict(trigger=res[0]))
-
-
-def drop(cursor, table):
+        bak_schema_table = ('%(backup_schema)s.%(table)s' %
+                            dict(backup_schema=backup_schema,
+                                 table=table))
+        rcount = count_rows(cursor, table)
+        print ('%(table)s (to be backed up) currently has %(rcount)s rows.'
+               % dict(table=table, rcount=rcount))
+
+        if rcount:
+            drop(cursor, bak_schema_table)
+            copy(cursor, table, bak_schema_table)
+            print ('%(bak_schema_table)s now has %(rows)s rows.' %
+                   dict(bak_schema_table=bak_schema_table,
+                        rows=count_rows(cursor, bak_schema_table)))
+
+
+def drop(cursor, schema_table):
+    print ('Dropping %(schema_table)s (%(rows)s rows).' %
+           dict(schema_table=schema_table,
+                rows=count_rows(cursor, schema_table)))
     try:
-        cursor.execute('drop table %(table)s' % dict(table=table))
-    except DatabaseError, e:
+        cursor.execute('drop table %(schema_table)s' %
+                       dict(schema_table=schema_table))
+    except DatabaseError, e:  # noqa
         # Table might not exist
         pass
 
 
-def has_rows(cursor, table):
-    ret = False
+def count_rows(cursor, schema_table):
+    ret = None
     try:
-        cursor.execute('select count(*) from %(table)s' %
-                       dict(table=table))
-        if int(cursor.fetchall()[0][0]) > 0:
-            ret = True
+        cursor.execute('select count(*) from %(schema_table)s' %
+                       dict(schema_table=schema_table))
+        ret = int(cursor.fetchall()[0][0])
     except:
         pass
     return ret
 
 
-def rename(cursor, table, new_name):
-    cursor.execute('alter table %(table)s rename to %(new_name)s' %
-                   dict(table=table, new_name=new_name))
+def copy(cursor, table, bak_schema_table):
+    print ('Copying %(table)s to %(bak_schema_table)s.' %
+           dict(table=table, bak_schema_table=bak_schema_table))
+    cursor.execute('create table %(bak_schema_table)s as '
+                   'select * from %(table)s' %
+                   dict(bak_schema_table=bak_schema_table, table=table))
 
 
 class MockCursor(object):
     def __init__(self):
-        self.fetch_count = 0
+        self.fetch_count = 1
 
     def execute(self, sql):
         print 'execute: ' + sql
@@ -75,17 +80,17 @@ def _tcb():
         from sys import argv
 
         def get_cursor():
-            host, port, sid = argv[1:4]
+            host, port, sid, backup_schema = argv[1:5]
             user = environ['pcornet_cdm_user']
             password = environ['pcornet_cdm']
 
             if '--dry-run' in argv:
-                return MockCursor()
+                return MockCursor(), backup_schema
             else:
                 import cx_Oracle as cx
                 conn = cx.connect(user, password,
                                   dsn=cx.makedsn(host, port, sid))
-                return conn.cursor()
+                return conn.cursor(), backup_schema
 
         main(get_cursor)
     _tcb()