<p><br /> On Jan 20, 2011 6:43 PM, "Tom Lane" <<a href="mailto:tgl@sss.pgh.pa.us">tgl@sss.pgh.pa.us</a>>
wrote:<br/> ><br /> > Robert Haas <<a href="mailto:robertmhaas@gmail.com">robertmhaas@gmail.com</a>>
writes:<br/> > > On Thu, Jan 20, 2011 at 11:55 AM, Stephen Frost <<a
href="mailto:sfrost@snowman.net">sfrost@snowman.net</a>>wrote:<br /> > >> While I agree completely about
thegeneral "if you're going to break,<br /> > >> break it big" approach, but I don't particularly care for
holdingoutput<br /> > >> strings from EXPLAIN to the same level that we do the wireline protocol.<br />
><br/> > > I agree; we make bigger changes than this all the time.<br /> ><br /> > No, we don't. It's
truethat a client that wants to truly *understand*<br /> > the plan has to know a lot of things, but the fundamental
formatof<br /> > EXPLAIN ANALYZE output has been real stable for a real long time:<br /> ><br /> > node name
(cost=xxx.xx..xxx.xxrows=xxx width=xxx) (actual time=xxx.xxx..xxx.xxx rows=xxx loops=xxx)<br /> > detail line:
somethingor other<br /> > -> subnode name ... more of the same ...<br /> ><br /> > This level of
understandingseems plenty sufficient for something like<br /> > <a
href="http://explain.depesz.com">explain.depesz.com</a>,to name just one popular tool. The last format<br /> >
changeof any kind we made in this skeleton was to increase the number<br /> > of decimal places in the "actual time"
numbersfrom 2 to 3 (wow).<br /> > That was in 7.4. Modulo that detail, this basic contract has been valid<br />
>since EXPLAIN ANALYZE was invented, in 7.2. As proposed, this patch<br /> > will break it.<br /> ><br />
>It might be interesting for somebody to go look at Hubert's code and see<br /> > just how much it really knows
aboutthe EXPLAIN output format, and how<br /> > much it's had to change across PG releases.<br /> ><p>Haven't
lookedat what changes with this patch, but dont forget PgAdmin that also parses the output. Though if the format
changesenough to affect it, that might be the driving force to have it use xml format instead, which is the one that is
intendedfor machine parsing after all.. <p>/Magnus