Re: [HACKERS] Re: Recursive use of syscaches (was: relation ### modified while in use)

[Hiroshi Inoue]

Tom Lane wrote: > Hiroshi Inoue <[EMAIL PROTECTED]> writes: > > My concern is the robustness of rel cache. > > It seems pretty dangerous to discard system relation > > descriptors used for cache mechanism especially in > > case of error recovery. > > It also seems pretty dangerous to recontruct relation > > descriptors especially in case of error recovery. > > Why? We are able to construct all the non-nailed relcache entries > from scratch during backend startup. That seems a sufficient > proof that we can reconstruct any or all of them on demand. > Hmm,why is it sufficent ? At backend startup there are no rel cache except some nailed rels. When 'reset system cache' message arrives,there would be many rel cache entries and some of them may be in use. In addtion there could be some inconsitency of db in the middle of the transaction. Is it safe to recon struct rel cache under the inconsistency ? Regards. Hiroshi Inoue