Re: SEARCH and CYCLE clauses

From: Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com>
To: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Cc: Vik Fearing <vik(at)postgresfriends(dot)org>
Subject: Re: SEARCH and CYCLE clauses
Date: 2020-07-03 07:08:26
Message-ID: c5603982-0088-7f14-0caa-fdcd0c837b57@2ndquadrant.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

While the larger patch is being considered, I think some simpler and
separable pieces could be addressed.

Here is a patch that adjusts the existing cycle detection example and
test queries to put the cycle column before the path column. The CYCLE
clause puts them in that order, and so if we added that feature that
would make the sequence of examples more consistent and easier to follow.

(And while the order of columns has no semantic meaning, for a human
left-to-right reader it also makes a bit more sense because the cycle
flag is computed against the previous path value, so it happens "before"
the path column.)

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Attachment Content-Type Size
0001-Adjust-cycle-detection-examples-and-tests.patch text/plain 12.3 KB

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Konstantin Knizhnik 2020-07-03 07:29:17 Re: Persist MVCC forever - retain history
Previous Message Pavel Stehule 2020-07-03 07:02:10 Re: track_planning causing performance regression