Richard Huxton wrote: > > Mark Morgan Lloyd wrote: > > If there's a risk that multiple clients will try to execute a 'create or > > replace function' simultaneously, what's the recommended practice for > > putting it in a transaction and/or locking it? If a lock's incolved what > > should this be applied to- the table that the function is most likely to > > be involved with, an arbitrary table, or a dummy table specifically > > reserved for this purpose? > > What problem are you trying to prevent here? Do you want a particular > version of the function to be available for a certain amount of time? I don't anticipate that the function will change, but it's (re)defined by a script triggered periodically on a client system. I'm pretty sure that I've seen a problem whilst I was doing maintenance when two clients tried to redefine it simultaneouly (i.e. on one of them the redefinition failed rather than waiting), in the interim I've set up a transaction with a lock on the table that is most likely to be involved noting that by default the lock type is the most restrictive. -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues]
