How to alter column (Changing datasize), if table was created with partitions? - ddl

Question

I have created table with a partition:
CREATE TABLE edw_src.pageviewlog_dev
(
accessurl character varying(1000),
msisdn character varying(1000),
customerid integer
)
WITH (
OIDS=FALSE
)
DISTRIBUTED BY (msisdn)
PARTITION BY RANGE(customerid)
(
PARTITION customerid START (0) END (200)
)
Now I want to change the datasize of accessurl from 1000 to 3000.I am not able to change the datasize,Whenever I am trying I am getting the error.
ERROR: "pageviewlog_dev_1_prt_customerid" is a member of a partitioning configurationHINT: Perform the operation on the master table.
I am able to change If I change the datatype from pg_attribute.If there any other way to change the datasize of existing column other than pg_attribute
I have found the Solution for the same .Sorry for the replying late .Below is the way to do ,whenever we face this kind of problem in "Post grel and greenplum"
UPDATE pg_attribute SET atttypmod = 300+4
WHERE attrelid = 'edw_src.ivs_hourly_applog_events'::regclass
AND attname = 'adtransactionid';

Answer 1

Greenplum isn't Postgresql so please don't confuse people by asking a Greenplum question with PostgreSQL in the title.
Don't modify catalog objects like pg_attribute. That will cause lots of problems and isn't supported.
The Admin Guide has the syntax for changing column datatypes and this is all you need to do:
ALTER TABLE edw_src.pageviewlog_dev
ALTER COLUMN accessurl TYPE character varying(3000);
Here is the working example with your table:
CREATE SCHEMA edw_src;
CREATE TABLE edw_src.pageviewlog_dev
(
accessurl character varying(1000),
msisdn character varying(1000),
customerid integer
)
WITH (
OIDS=FALSE
)
DISTRIBUTED BY (msisdn)
PARTITION BY RANGE(customerid)
(
PARTITION customerid START (0) END (200)
);
Output:
NOTICE: CREATE TABLE will create partition "pageviewlog_dev_1_prt_customerid" for table "pageviewlog_dev"
Query returned successfully with no result in 47 ms.
And now alter the table:
ALTER TABLE edw_src.pageviewlog_dev
ALTER COLUMN accessurl TYPE character varying(3000);
Output:
Query returned successfully with no result in 62 ms.
Proof in psql:
\d edw_src.pageviewlog_dev
Table "edw_src.pageviewlog_dev"
Column | Type | Modifiers
------------+-------------------------+-----------
accessurl | character varying(3000) |
msisdn | character varying(1000) |
customerid | integer |
Number of child tables: 1 (Use \d+ to list them.)
Distributed by: (msisdn)
If you are unable to alter the table it is probably because the catalog is corrupted after you updated pg_attribute directly. You can try dropping the table and recreating it or you can open a support ticket to have them attempt to correct the catalog corruption.