Re: xlog location arithmetic

On Fri, Mar 9, 2012 at 16:37, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Fri, Mar 9, 2012 at 9:55 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> Actually ... now that I look at it, isn't it completely bogus to be
>>> using numeric for the result of pg_xlog_location_diff?
>
>> rhaas=# select pg_xlog_location_diff('ffffffff/0', '0/0')::int8;
>> ERROR:  bigint out of range
>
> Oh ... I see my mistake.  I was looking at this:
>
>        /*
>         * result = XLogFileSize * (xlogid1 - xlogid2) + xrecoff1 - xrecoff2
>         */
>
> and confusing XLogFileSize with XLogSegSize.  Not the best choice of
> names.

Yeah, the use of XLogFile to mean something other than, well a file in
the xlog, is greatly annoying.. I guess we could change it, but it
goes pretty deep in the system so it's not a small change...

--
 Magnus Hagander
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