Bruce Momjian wrote: > Joe Conway wrote: >>This is basically Tom's proposal, but substituting MUTATED for the >>original command tag name acknowledges that the original command was not >> executed unchanged. It also serves as a warning that the affected >>tuple count is from one or more substitute operations, not the original >>command. > > Any suggestion on how to show the tag mutated? Do we want to add more > tag possibilities?
The suggestion was made based on what I think is the desired behavior, but I must admit I have no idea how it would be implemented at this point. It may turn out to be more pain than it's worth. >>I don't know about that. The number of "rows affected" is indeed this >>number. It's just that they were not all affected in the same way. > > Yes, that is true. The problem is that a DELETE returning a value of 10 > may have deleted only one row and updated another 9 rows. In such > cases, returning 1 is better. Of course, if there are multiple deletes > then perhaps the total is better, but then again, there is no way to > flag this so we have to do one or the other consistently. > > The real problem which you outline is that suppose the delete does _no_ > deletes but only inserts. In my plan, we would return zero while in > yours you would return the rows updated. > > In my view, if you return a delete tag, you better only count deletes. > > Also, your total affected isn't going to work well with INSERT because > we could return a non-1 for rows affected and still return an OID, which > would be quite confusing. I did the total only matching tags because it > does mesh with the INSERT behavior. Sure, but that's why I am in favor of changing the tag. If you did: DELETE FROM fooview WHERE name LIKE 'Joe%'; and got: MUTATED 507324 3 it would mean that 3 tuples in total were affected by all of the substitute operations, only of of them being an INSERT, and the Oid of the lone INSERT was 507324. If instead I got: DELETE 0 I'd be back to having no useful information. Did any rows in fooview match the criteria "LIKE 'Joe%'"? Did any data in my database get altered? Can't tell from this. Joe ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
