Обсуждение: Where does catalog store CHAR length ?

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Where does catalog store CHAR length ?

От

"phd9110"

Дата:

01 декабря 2003 г., 06:36:38

hi
the table pg_attribute have the attribute "attlen" , and this attribute will
store the attribute length. For example , when integer , this value will be 4.
But if attribute type is Char(xx), this value will be -1. This is because it
reference the bychar in pg_type table.

So, where is the Char() length information store ??
and what time will system check this string length constraint ?

thanks for your help!
Kao , Nchu Taiwan

Re: Where does catalog store CHAR length ?

От

Alvaro Herrera

Дата:

01 декабря 2003 г., 09:33:22

On Mon, Dec 01, 2003 at 06:31:56PM +0800, phd9110 wrote:

>  the table pg_attribute have the attribute  "attlen" , and this attribute will
> store the attribute length. For example , when integer , this value will be 4.
> But if attribute type is Char(xx), this value will be -1. This is because it
> reference the bychar in pg_type table.
> 
> So, where is the Char() length information store ??

atttypmod is the maximum length + 4.

-- 
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"El destino baraja y nosotros jugamos" (A. Schopenhauer)

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Обсуждение: Where does catalog store CHAR length ?

Where does catalog store CHAR length ?

Re: Where does catalog store CHAR length ?