On Tue, May 20, 2025 at 3:09 PM Maciek Sakrejda <mac...@pganalyze.com> wrote: > +1, this seems like it could be very useful. A somewhat related issue > is being able to tie plan nodes back to the query text: it can be hard > to understand the planner's decisions if it's not even clear what part > of the query it's making decisions about. I'm sure this is not an easy > problem in general, but I wonder if you think that could be improved > in the course of this work, or if you have other thoughts about it.
Thanks. I don't really have any ideas about the problem you mention, perhaps partly because I haven't experienced it too much. I mean, I have sometimes been confused about which parts of the query go with which parts of the EXPLAIN, but I think in my experience so far that is mostly because either (1) both the query and the EXPLAIN output are super long and maybe also super-wide and therefore it's hard to correlate things by eye or (2) somebody wrote a query where they use the same table and/or table alias over and over again in different parts of the query and so it's hard to tell which reference goes with which. Neither of those problems seems all that exciting to me from a dev perspective: if you're calling everything a or x or orders or something, maybe don't do that, and if your query is 1500 characters long, I guess you need to budget some time to align that with the query plan. I don't really know how much we can do here. But maybe there are cases that I haven't seen where something better is possible, or perhaps you have some good idea that I haven't considered. (If I'm honest, I do have an idea that I think might very significantly improve the readability of EXPLAIN output. I think it would make it much less wide in normal cases without making it much longer. This has been percolating in my brain for a few years now and I have the vague intention of proposing it at some point, but not until I'm good and ready to be flamed to a well-done crisp, because I'm quite sure there will be more than one opinion on the merits.) -- Robert Haas EDB: http://www.enterprisedb.com
