Thread: Ignore Some Updates

Dear developers,

I wonder it happens to systems where inefficient update
SQL's are used like this:

UPDATE MyTable SET MyColumn=1234

Question arises when the value of MyColumn is already 1234
before the update.

If I am right, even when the to-be-updated column values
equal to the new values, the core never hates to update that
row anyway. If so, is it wise or not to adjust the core for
lazy SQL users to ignore such "meaningless" updates in order
to reduce some disk load and prevent some "holes" resulted
from the delete (a consequence of update) in that table?

Regards,
CN

"cnliou" <cnliou@so-net.net.tw> writes:
> I wonder it happens to systems where inefficient update
> SQL's are used like this:
> UPDATE MyTable SET MyColumn=1234
> Question arises when the value of MyColumn is already 1234
> before the update.

We have to fire UPDATE triggers in any case.

> If I am right, even when the to-be-updated column values
> equal to the new values, the core never hates to update that
> row anyway. If so, is it wise or not to adjust the core for
> lazy SQL users to ignore such "meaningless" updates in order

Seems like penalizing the intelligent people (by adding useless
comparisons) in order to reward the "lazy" ones.

            regards, tom lane