Re: Error handling in plperl and pltcl

Jan,

> ... plus that the catch-nesting automatically represents the 
> subtransaction nesting. I can't really see any reason why those two 
> should not be bound together. Does anybody?

That depends on what you mean. As a stop-gap solution, cerntanly. But in 
the long run, I still think that savepoints and exception handling 
should be kept separate. Consider the following two examples:

savepoint a
spi calls
savepoint b
spi calls
savepoint c
spi calls

switch(some test)
{case 1:   rollback b;   commit a;   break; case 2:   rollback c;   commit a;   break; case 3:   rollback a;   break;
default:   commit a;
 
}

or nested try/catch where the catch doesn't access the database:

foo()
{  try  {       spi calls;   }   catch   {       set some status;       re-throw;   }
}

and some other place in the code:
  savepoint a  try  {    spi calls;    for(i = 0; i < 100; ++i)        foo();    commit a;  }  catch  {     rollback a;
}
 

If "normal" savepoint hanling is disabled here in favor of your 
suggestion, you will get 101 subtransations although only 1 is relevant.

I still think that the concept of savepoints is fairly easy to 
understand. Using it together with exception handling is a common and 
well known concept and we can make it even more so by providing good 
documentation and examples.

Regards,
Thomas Hallgren