1ALTER TABLE ONLY trends
2	ALTER COLUMN value_min TYPE DOUBLE PRECISION,
3	ALTER COLUMN value_min SET DEFAULT '0.0000',
4	ALTER COLUMN value_avg TYPE DOUBLE PRECISION,
5	ALTER COLUMN value_avg SET DEFAULT '0.0000',
6	ALTER COLUMN value_max TYPE DOUBLE PRECISION,
7	ALTER COLUMN value_max SET DEFAULT '0.0000';
8ALTER TABLE ONLY history
9	ALTER COLUMN value TYPE DOUBLE PRECISION,
10	ALTER COLUMN value SET DEFAULT '0.0000';
11