Cats, Dogs, and ORA-01555
More on the favorite ORA-01555 error.
The ORA-01555 (snapshot too old) error message..itself is somehting that rarely seems to occur in development and testing environments, but pops up with maddening frequency in production...the obvious solution: Use larger rollback segments...From an application developer’s perspective, that seems simple and straightforward enough!
However, ...a DBA disputes this logical conclusion, despite the evidence of the documentation. He..asks to see the SQL statement in question, promptly finds something the matter with it, and insists that the rollback segments do not need be made larger. Absurd as it sounds, the DBA instead recommends various unrelated courses of action, all geared toward “tuning” the SQL statement. Since the problem cannot be reproduced in development or test environments, changes might have to be tested in production.
In reality, while the probability of encountering the error can be greatly reduced by following the course of action described in the documentation, the reality is that it is rarely feasible to devote sufficient space on a busy production system for this purpose.
The real solution for this problem is very much individual to the SQL statement encountering it and the application system in which it is running.
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