Re: Proposal: "Causal reads" mode for load balancing reads without stale data

Hi Thomas,

On 2016/02/29 15:20, Thomas Munro wrote:
> Thanks for looking at the patch!  Here is a new version with the
> following changes:
> 
> 1.  Some draft user documentation has been added, as requested.

Just to clarify, in:

+         servers.  A transaction that is run with
<varname>causal_reads</> set
+         to <literal>on</> is guaranteed either to see the effects of all
+         completed transactions run on the primary with the setting on, or to
+         receive an error "standby is not available for causal reads".

"A transaction that is run" means "A transaction that is run on a
standby", right?  By the way, is there some discussion in our existing
documentation to refer to about causal consistency in single node case?  I
don't know maybe that will help ease into the new feature.  Grepping the
existing source tree doesn't reveal the term "causal", so maybe even a
single line in the patch mentioning "single node operation trivially
implies (or does it?) causal consistency" would help.  Thoughts?

Thanks,
Amit