On Thu, Sep 05, 2019 at 03:17:51PM -0400, Robert Haas wrote: > Oops. Yeah, that's bogus (as are some of the other things you > mention). I think we're going to have to fix this by passing down > some flags to these functions to tell them what kind of progress > updates to do (or to do none). Or else pass down a callback function > and a context object, but that seems like it might be overkill.
One idea I got was to pass the command ID as an extra argument of the update routine. I am not completely sure either if we need this level of complication. > Those are just weaknesses of the infrastructure. Perhaps there is a > better solution, but there's no intrinsic reason that we can't avoid > them by careful coding. Perhaps. The current infra allows the addition of a progress report in code paths which are isolated from other things. For CLUSTER, most things are fine as long as the progress is updated in cluster_rel(), the rest is too internal. > Well, it might be OK to do that if we're clear that this is the index > progress-reporting view and the command is CLUSTER but it happens to > be building an index now so we're showing it here. But I don't see > how it would work anyway: you can't reported cascading progress > reports in shared memory because you've only got a fixed amount of > space. I don't see exactly why we could not switch to a fixed number of slots, say 8, with one code path to start a progress which adds an extra report on the stack, one to remove one entry from the stack, and a new one to reset the whole thing for a backend. This would not need much restructuration of course. Finally comes the question of what do we do for v12? I am adding in CC Peter, Alvaro being already present, who have been involved in the commits with CREATE INDEX and REINDEX. It would be sad to revert a this feature, but well I'd rather do that now than regret later releasing the feature as it is currently shaped.. Let's see what the others think. -- Michael
signature.asc
Description: PGP signature
