On Tue, Jul 10, 2012 at 10:44 AM, Tom Lane <t...@sss.pgh.pa.us> wrote:
> Greg Stark <st...@mit.edu> writes: > > On Sat, Jul 7, 2012 at 4:53 AM, Gurjeet Singh <singh.gurj...@gmail.com> > wrote: > >> All we need to do is allow swapping of pg_class.relfilenode of two > indexes. > > > Fwiw I don't like swapping relfilenodes on indexes the user created. > > REINDEX currently does this but it's a bit of a hack and only works > > because reindex carefully builds the new index with exactly the same > > definition as the old one. > > Yes. The swap-relfilenodes operation would have to carefully check that > the index definitions were exactly equivalent, and there would be a > constant risk for bugs of omission if that code weren't taught about > any new index properties we invent. > IMHO there must be many other places in this code-base where we run that risk. The way I am planning to do it was to compare all relevant fields of the FormData_pg_index. And I am assuming anybody changing the struct members will take care of relevant changes needed for this code too. We can add a runtime/compile-time assert to make sure that Natts_pg_index==17. That way, if a new column gets added, we will get alerted promptly. > All of these things seem like ugly, hard-to-use kluges anyway (the > make-sure-the-indexes-match business is just as much of a PITA for the > DBA as it is for the system). What we really want is REINDEX > CONCURRENTLY. > +1, but I can't take on that task. -- Gurjeet Singh EnterpriseDB Corporation The Enterprise PostgreSQL Company
