Re: Regarding varchar max length in postgres

On 10/15/18 8:56 AM, Durgamahesh Manne wrote:
> 
> 
> On Mon, Oct 15, 2018 at 9:07 PM David G. Johnston 
> <david.g.johnston@gmail.com <mailto:david.g.johnston@gmail.com>> wrote:
> 
>     On Mon, Oct 15, 2018 at 8:24 AM Durgamahesh Manne
>     <maheshpostgres9@gmail.com <mailto:maheshpostgres9@gmail.com>> wrote:
> 
>         So i need unlimited length data type for required column of the
>         table for storing the large values
>         is there any issue to use unlimited length datatype  text  for
>         the required column of the table instead of using varchar ?
> 
> 
>     Between the two you should use the "text" data type for those
>     columns.  You will need to describe your use case in more detail if
>     you want input as to whether you need to use the large object API
>     instead.
> 
>     The database cannot store an unlimited amount of data in a single
>     row+column (cell) - you will still encounter a physical limit to the
>     number of bytes able to be stored in a single cell when using text.
> 
>     David J.
> 
> 
> 
> Hi sir
> 
>   i need to store more values on required column of the table by using 
> text  than varchar
> 
> you said that physical limit needs to be stored values  in column of the 
> table
> 
> |text|    variable unlimited length

There are two limits at work here. n in varchar(n) and char(n) is the 
number of characters that can be stored. Text does not have the ability 
to limit the characters on declaration. In the special case of varchar 
(no n declared) it is equal to text. All the character types(varchar, 
char, text) have a storage limit of 1GB per field. This storage value is 
not necessarily a one to one relationship to n as the encoding for the 
string maybe a multibyte one and a character may occupy multiple bytes.





> 
> 
> 
> ype
> Thank you for this valuable information
> 
>   PostgreSQL is always no 1 world s leading open source  RDBMS
> 
> 
> 
>   I request you all community members to provide built in bdr v3 version 
> replication for public as multimaster replication is on high priority  
> against other dbms


-- 
Adrian Klaver
adrian.klaver@aklaver.com