Thread

Re: How to alter the size of a column

mikeo <mikeo@spectrumtelecorp.com> — 2000-08-01T18:52:19Z

sorry, forgot to include this address...

>Date: Tue, 01 Aug 2000 14:51:03 -0400
>To: "Cheng Kai" <chengk@isse.kuis.kyoto-u.ac.jp>
>From: mikeo <mikeo@spectrumtelecorp.com>
>Subject: Re: [GENERAL] How to alter the size of a column  
>In-Reply-To: <002301bffb6a$63dcc0a0$9b0210ac@cembaro>
>References: <200008010045.RAA22022@cyberpass.net>
<398625F7.C22A345C@nimrod.itg.telecom.com.au>
>
>hi, i changed the size of a column using this method:
>
>tig4=# \d cust
>                                Table "cust"
>     Attribute     |    Type     |                 Modifier
>-------------------+-------------+------------------------------------------
> cust_id           | varchar(15) | not null
> cut_id            | varchar(6)  | not null
> cust_name         | varchar(50) | not null
> cust_division     | varchar(6)  |
> cust_svc_start_dt | date        | not null default now()
> cust_svc_end_dt   | date        |
> cust_valid        | char(1)     | not null default 'Y'
> cust_bill_loc_id  | varchar(6)  | not null
> wu_id             | varchar(10) | not null default 'SPECTRUM'
> cust_timestamp    | timestamp   | not null default now()
> agt_id            | varchar(10) | default 'DEFAULT'
> rse_id            | integer     |
> bd_id             | varchar(6)  | not null
> cust_email        | varchar(50) |
> cust_stream       | integer     | default nextval('cust_stream_seq'::text)
> br_cycle          | integer     |
> cust_qr_reports   | varchar(20) |
> cust_qr_sent      | timestamp   |
>Indices: cust_cut_idx,
>         cust_pkey,
>         cust_stream_idx
>
>update pg_attribute set atttypmod = 19 where attname = 'cut_id' where
attrelid = 
>(select oid from pg_class where relname = 'cust');
>
>
>tig4=# \d cust
>                                Table "cust"
>     Attribute     |    Type     |                 Modifier
>-------------------+-------------+------------------------------------------
> cust_id           | varchar(15) | not null
> cut_id            | varchar(15)  | not null
> cust_name         | varchar(50) | not null
> cust_division     | varchar(6)  |
> cust_svc_start_dt | date        | not null default now()
> cust_svc_end_dt   | date        |
> cust_valid        | char(1)     | not null default 'Y'
> cust_bill_loc_id  | varchar(6)  | not null
> wu_id             | varchar(10) | not null default 'SPECTRUM'
> cust_timestamp    | timestamp   | not null default now()
> agt_id            | varchar(10) | default 'DEFAULT'
> rse_id            | integer     |
> bd_id             | varchar(6)  | not null
> cust_email        | varchar(50) |
> cust_stream       | integer     | default nextval('cust_stream_seq'::text)
> br_cycle          | integer     |
> cust_qr_reports   | varchar(20) |
> cust_qr_sent      | timestamp   |
>Indices: cust_cut_idx,
>         cust_pkey,
>         cust_stream_idx
>
>
>
>the number in atttypmod is 4 larger because it's a varchar column that i'm
>working with in this instance and the system uses those 4 bytes to keep 
>track of the variable length of the column.  i've never changed any other
>type of field, such as date or integer and i've only ever increased a 
>varchar field.  i'm sure that you'd have a problem if you try to reduce 
>it and the table has values in there that are the current max size.
>
>mikeo
>
>  
>At 12:41 PM 8/1/00 +0900, you wrote:
>>Hi,
>>
>>     I want to alter the size of a column, say from char(40) to char(80),
>>but it seem that
>>the  ALTER does not support such operation, nor does it support column
>>removing.
>>
>>     How can I do for this ?
>>
>>
>>     Thanks
>>