Re: Behavior of the "Explain query" button with multiple queries in the window

Hi,

2014-07-22 20:33 GMT+02:00 Nicolas Anonyme <pathogenyx(at)gmail(dot)com>:

> Hello,
>
> Today, one of my coworker was preparing several "update" and "insert"
> queries, in a query window, and he pressed the "Explain query" button
> to check the query plan, expecting it to be inoffensive.
> He then sent me the requests to play them, but I immediately got some
> errors about duplicate primary keys. After checking the related data,
> all but one had been changed.
> « - Hey, are you sure you did not already played the queries by error ?
> - Yes, I only did an "explain" ... what the heck?... »
> Hilarity ensues (I had luckily made a backup of the data just before).
>
> The "Explain query" button seems to add an "EXPLAIN" keyword at the
> start of the text so it only explains the first query, but other
> queries will be simply played on the database.
>
> So ok it was a bad idea, but we were wondering if it was the wisest
> behavior or if maybe some countermeasures could be added in order to
> enforce principle of least astonishment for layman users, like us.
>
> Maybe like, :
> * when pressing that button, only "explain" the first query of the
> text field, and ignore the following queries + display a warning in
> the message panel (I think it would be the best solution, imho, but I
> guess it would need a basic syntactical parser to find the end of the
> first query),
>

Yeah, and that's not gonna happen anytime soon.

> * change the tooltip of the button ("explain the first query, play
> the next ones")
>

Funny, but no :)

Almost nobody reads message boxes... nobody will read the tooltip.

* add a pop-up warning if it seems to have several queries (« We said
> "explain query" not "explain queries", do you still want to continue
> ?»)
>

That's probably the one I prefer. You still need a parser of some sort
though.

> * explain all the queries! (but I guess it would be a bit difficult
> to implement without major UI and logic refactoring)
>

Oh yeah. Not gonna happen.

> * a better solution that I did not think of :)
>

You already had quite a lof of suggestions :)

> * no solution, because "it works like intended" (but I'd then
> respectfully disagree on the intuitiveness of the feature)
>
>
Well, it works as expected. And I agree this isn't intuitive. Though I
wonder what your colleague expects launching an EXPLAIN on a number of
queries? we won't draw all query plans, that has not much sense to me.

--
Guillaume.
http://blog.guillaume.lelarge.info
http://www.dalibo.com