--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pydbkit/pgdatacopy.py	Wed Jul 09 18:03:54 2014 +0200
@@ -0,0 +1,116 @@
+# -*- coding: utf-8 -*-
+#
+# PgDataCopy - copy data between tables
+#
+# Copyright (c) 2012  Radek Brich <radek.brich@devl.cz>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+
+import io
+
+
+class TargetNotEmptyError(Exception):
+    
+    def __init__(self, msg, table):
+        Exception.__init__(self, msg)
+        self.table = table
+
+
+class PgDataCopy:
+    
+    def __init__(self, conn1, conn2):
+        self.conn1 = conn1
+        self.conn2 = conn2
+        self.fulltable1 = None
+        self.fulltable2 = None
+   
+    def set_source(self, table, schema='public'):
+        self.schema1 = schema
+        self.table1 = table
+        self.fulltable1 = '"' + schema + '"."'+ table + '"'
+    
+    def set_destination(self, table, schema='public'):
+        self.schema2 = schema
+        self.table2 = table
+        self.fulltable2 = '"' + schema + '"."'+ table + '"'
+    
+    def copy(self):
+        self.check()
+        
+        buf = io.StringIO()
+        try:
+            self.read(buf)
+            data = buf.getvalue()
+        finally:
+            buf.close()
+        
+        buf = io.StringIO(data)
+        try:
+            self.write(buf)
+        finally:
+            buf.close()
+        
+        self.analyze()
+    
+    def check(self):
+        '''Check that target table does not contain any data (otherwise cannot copy).'''
+        q = self._compose_check(self.fulltable2)
+        curs = self.conn2.cursor()
+        curs.execute(q)
+        curs.connection.commit()
+        if curs.rowcount > 0:
+            raise TargetNotEmptyError('Target table contains data.', self.fulltable2)
+        self.cols = [desc[0] for desc in curs.description]
+    
+    def read(self, tmpfile):
+        '''Read contents from source table.'''
+        q = self._compose_read(self.fulltable1, self.cols)
+        curs = self.conn1.cursor()
+        curs.copy_expert(q, tmpfile)
+        curs.connection.commit()
+    
+    def write(self, tmpfile):
+        '''Write source table contents to target table.'''
+        q = self._compose_write(self.fulltable2, self.cols)
+        curs = self.conn2.cursor()
+        curs.copy_expert(q, tmpfile)
+        curs.connection.commit()
+    
+    def analyze(self):
+        '''Analyze target table.'''
+        q = self._compose_analyze(self.fulltable2)
+        curs = self.conn2.cursor()
+        curs.execute(q)
+        curs.connection.commit()
+    
+    def _compose_check(self, table):
+        return 'SELECT * FROM %s LIMIT 1' % table
+    
+    def _compose_read(self, table, cols):
+        collist = ', '.join(['"%s"' % col for col in cols])
+        return 'COPY %s (%s) TO STDOUT' % (table, collist)
+    
+    def _compose_write(self, table, cols):
+        collist = ', '.join(['"%s"' % col for col in cols])
+        return 'COPY %s (%s) FROM STDIN' % (table, collist)
+    
+    def _compose_analyze(self, table):
+        return 'ANALYZE %s' % table
+