> For starters, the use-case hasn't been explained to my satisfaction. > In what situation is it actually helpful to TRUNCATE a table that's > not there yet? Aren't you going to have to do a CREATE IF NOT EXISTS > to keep from failing later in the script? If so, why not just do that > first?
There is a use case for the truncate 'mutliple' tables, maybe less clear for a single table. Sébastien will speak here I suppose. > Second, to my mind the point of a multi-table TRUNCATE is to ensure that > all the referenced tables get reset to empty *together*. With something > like this, you'd have no such guarantee. Consider a timeline like this: > > Session 1 Session 2 > > TRUNCATE IF EXISTS a, b, c; > ... finds c doesn't exist ... > ... working on a and b ... > CREATE TABLE c ( ... ); > INSERT INTO c ...; > ... commits ... > > Now we have a, b, and c, but c isn't empty, violating the expectations > of session 1. So even if there's a use-case for IF EXISTS on a single > table, I think it's very very dubious to allow it in multi-table > commands. well, in such case you probably don't want to use IF EXISTS. -- Cédric Villemain +33 (0)6 20 30 22 52 http://2ndQuadrant.fr/ PostgreSQL: Support 24x7 - Développement, Expertise et Formation
