Обсуждение: Bug?

Indira Muthuswamy wrote:
> Hai,
>  
>  I have encountered a problem with PostgreSQL.I have created a table 
> 'tab1' with a column 'a' with serial type.I entered 20 records into 
> the  table.So the query
>   select max(a) from tab1;
> returned 20.When I tried the same query after the command
>  truncate table tab1;
> I found that the output of the first query as
>  
>  max
> -----
>
> (1 row)
>
> When I tried to insert a new row into the table tab1 I found that the 
> value at column a incremented to the value 21.
> But I heard from my friends that the value of the serial column gets 
> decremented whenever we issue the 'truncate table' command (in MS SQL 
> SERVER).Is the concept same with PostgreSQL or not?Can anyone clarify 
> me on this?
>  

Sure. You heard wrong about postgres.

Please do not ask questions like this on the -hackers list - this should 
have gone to pgsql-general. The hackers list is for postgresql 
development discussions only.

cheers

andrew

Moving to -sql.

On Wed, Oct 18, 2006 at 06:53:46PM +0530, Indira Muthuswamy wrote:
> Hai,
> 
> I have encountered a problem with PostgreSQL.I have created a table
> 'tab1' with a column 'a' with serial type.I entered 20 records into the
> table.So the query
>  select max(a) from tab1;
> returned 20.When I tried the same query after the command
> truncate table tab1;
> I found that the output of the first query as
> 
> max
> -----
> 
> (1 row)
> When I tried to insert a new row into the table tab1 I found that the
> value at column a incremented to the value 21.
> But I heard from my friends that the value of the serial column gets
> decremented whenever we issue the 'truncate table' command (in MS SQL
> SERVER).Is the concept same with PostgreSQL or not?Can anyone clarify me on
> this?

Your friends are mistaken. TRUNCATE does nothing to affect sequences.
-- 
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)