Обсуждение: newbieish exception/multilevel transactions

Hi,

I was wondering, is it a possibility/projected to have nested transactions
in postgres? Would MVCC support that?

What I would like is following:
begin tran a; do some work; begin tran b;   do some other work rollback b;
<at this point, only changes by transaction b are rolled back>
... 
commit a;

Alternatively, is there a way to trap an exception in plpgsql? [I would
assume that depends on SPI ability to trap exceptions...]

These features are really needed for people who do serious
database-backend scripting, to compete with sybase (who has multilevel
transactions) and oracle (who has very good exception handling).

Thank you
-alex

Savepoints will be implemented after WAL.

Vadim

> I was wondering, is it a possibility/projected to have nested 
> transactions in postgres? Would MVCC support that?
> 
> What I would like is following:
> begin tran a;
>   do some work;
>   begin tran b;
>     do some other work
>   rollback b;
> <at this point, only changes by transaction b are rolled back>
> ... 
> commit a;
> 
> Alternatively, is there a way to trap an exception in 
> plpgsql? [I would assume that depends on SPI ability to trap
exceptions...]
> 
> These features are really needed for people who do serious
> database-backend scripting, to compete with sybase (who has multilevel
> transactions) and oracle (who has very good exception handling).
> 
> Thank you
> 
>  -alex
>