|From:||Etsuro Fujita <fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp>|
|Subject:||Re: We need to support ForeignRecheck for late row locking, don't we?|
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On 2015/07/22 19:10, Etsuro Fujita wrote:
> While working on the issue "Foreign join pushdown vs EvalPlanQual", I
> happened to notice odd behaviors of late row locking in FDWs.
> I think the reason for that is because we don't check pushed-down quals
> inside an EPQ testing even if what was fetched by RefetchForeignRow was
> an updated version of the tuple rather than the same version previously
> obtained. So, to fix this, I'd like to propose that pushed-down quals
> be checked in ForeignRecheck.
Attached is a patch for that.
* I've modified ForeignRecheck so as to check pushed-down quals whether
doing late locking or early locking. I think we could probably make
ForeignRecheck do so only when doing late locking, but I'm not sure it's
worth complicating the code.
* I've made the above change only for simple foreign table scans that
have scanrelid > 0 and fdw_scan_tlist = NIL. As for simple foreign
table scans that have scanrelid > 0 and *fdw_scan_tlist is non-NIL*, I
think we are under discussion in another thread I started. Will update
* Sorry, I've not fully updated comments and docs yet. Will update.
I'd be happy if I could get feedback earlier.
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