Postgres Conference China 2016 中国用户大会 MQ-Prototype KAFKA-MQ-Solution Cluster BackupData:2 Producer Producer Consumer DB dist-cluser multi single cluser broker1 broker2 brokerN … DB1

__iter__ and next methods) CREATE FUNCTION greet (how text) RETURNS SETOF greeting AS $$ class producer: def __init__ (self, how, who): self.how = how self.who = who self.ndx = -1 def __iter__ (self): if self.ndx == len(self.who): raise StopIteration return ( self.how, self.who[self.ndx] ) return producer(how, [ "World", "PostgreSQL", "PL/Python" ]) $$ LANGUAGE plpythonu; 743 Chapter 40. PL/Python USING clause. For example, to delete all films produced by a given producer, one might do DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially

__iter__ and next methods) CREATE FUNCTION greet (how text) RETURNS SETOF greeting AS $$ class producer: def __init__ (self, how, who): self.how = how self.who = who self.ndx = -1 def __iter__ (self): if self.ndx == len(self.who): raise StopIteration return ( self.how, self.who[self.ndx] ) return producer(how, [ "World", "PostgreSQL", "PL/Python" ]) $$ LANGUAGE plpythonu; 743 Chapter 40. PL/Python USING clause. For example, to delete all films produced by a given producer, one might do DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially

__iter__ and next methods) CREATE FUNCTION greet (how text) RETURNS SETOF greeting AS $$ class producer: def __init__ (self, how, who): self.how = how self.who = who self.ndx = -1 def __iter__ (self): if self.ndx == len(self.who): raise StopIteration return ( self.how, self.who[self.ndx] ) return producer(how, [ "World", "PostgreSQL", "PL/Python" ]) $$ LANGUAGE plpythonu; 839 Chapter 41. PL/Python USING clause. For example, to delete all films produced by a given producer, one can do: DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially

__iter__ and next methods) CREATE FUNCTION greet (how text) RETURNS SETOF greeting AS $$ class producer: def __init__ (self, how, who): self.how = how self.who = who self.ndx = -1 def __iter__ (self): if self.ndx == len(self.who): raise StopIteration return ( self.how, self.who[self.ndx] ) return producer(how, [ "World", "PostgreSQL", "PL/Python" ]) $$ LANGUAGE plpythonu; Generator (yield) CREATE FUNCTION USING clause. For example, to delete all films produced by a given producer, one can do: DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially

the WHERE condition. For example, to delete all films produced by a given producer, one might do DELETE FROM films WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially happening deletion. This syntax is not standard. A more standard way to do it is DELETE FROM films WHERE producer_id IN (SELECT id FROM producers WHERE name = ’foo’); In some cases the join style is easier to

the WHERE condition. For example, to delete all films produced by a given producer, one might do DELETE FROM films WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially happening deletion. This syntax is not standard. A more standard way to do it is DELETE FROM films WHERE producer_id IN (SELECT id FROM producers WHERE name = ’foo’); In some cases the join style is easier to

__iter__ and next methods) CREATE FUNCTION greet (how text) RETURNS SETOF greeting AS $$ class producer: def __init__ (self, how, who): self.how = how self.who = who self.ndx = -1 def __iter__ (self): if self.ndx == len(self.who): raise StopIteration return ( self.how, self.who[self.ndx] ) return producer(how, [ "World", "PostgreSQL", "PL/Python" ]) $$ LANGUAGE plpythonu; Generator (yield) CREATE FUNCTION USING clause. For example, to delete all films produced by a given producer, one can do: DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially

__iter__ and next methods) CREATE FUNCTION greet (how text) RETURNS SETOF greeting AS $$ class producer: def __init__ (self, how, who): self.how = how self.who = who self.ndx = -1 def __iter__ (self): if self.ndx == len(self.who): raise StopIteration return ( self.how, self.who[self.ndx] ) return producer(how, [ "World", "PostgreSQL", "PL/Python" ]) $$ LANGUAGE plpythonu; 921 Chapter 41. PL/Python USING clause. For example, to delete all films produced by a given producer, one can do: DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially

USING clause. For example, to delete all films produced by a given producer, one might do DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = ’foo’; What is essentially deletion. This syntax is not standard. A more standard way to do it is DELETE FROM films WHERE producer_id IN (SELECT id FROM producers WHERE name = ’foo’); In some cases the join style is easier to