čt 14. 1. 2021 v 18:09 odesílatel Dian M Fay <dian.m....@gmail.com> napsal:
> On Thu Jan 14, 2021 at 10:04 AM EST, Dmitry Dolgov wrote: > > > On Tue, Jan 12, 2021 at 08:02:59PM +0100, Pavel Stehule wrote: > > > ne 10. 1. 2021 v 19:52 odesílatel Pavel Stehule < > pavel.steh...@gmail.com> > > > napsal: > > > > > > I tested behaviour and I didn't find anything other than the mentioned > > > issue. > > > > > > Now I can check this feature from plpgsql, and it is working. Because > there > > > is no special support in plpgsql runtime, the update of jsonb is > > > significantly slower than in update of arrays, and looks so update of > jsonb > > > has O(N2) cost. I don't think it is important at this moment - more > > > important is fact, so I didn't find any memory problems. > > > > Thanks for testing. Regarding updates when the structure doesn't match > > provided path as I've mentioned I don't have strong preferences, but on > > the second though probably more inclined for returning an error in this > > case. Since there are pros and cons for both suggestions, it could be > > decided by vote majority between no update (Dian) or an error (Pavel, > > me) options. Any +1 to one of the options from others? > > > > Other than that, since I've already posted the patch for returning an > > error option, it seems that the only thing left is to decide with which > > version to go. > > The trigger issue (which I did verify) makes the "no update" option > unworkable imo, JavaScript's behavior notwithstanding. But it should be > called out very clearly in the documentation, since it does depart from > what people more familiar with that behavior may expect. Here's a quick > draft, based on your v44 patch: > > <para> > <type>jsonb</type> data type supports array-style subscripting expressions > to extract or update particular elements. It's possible to use multiple > subscripting expressions to extract nested values. In this case, a chain > of > subscripting expressions follows the same rules as the > <literal>path</literal> argument in <literal>jsonb_set</literal> function, > e.g. in case of arrays it is a 0-based operation or that negative integers > that appear in <literal>path</literal> count from the end of JSON arrays. > The result of subscripting expressions is always of the jsonb data type. > </para> > <para> > <command>UPDATE</command> statements may use subscripting in the > <literal>SET</literal> clause to modify <type>jsonb</type> values. Every > affected value must conform to the path defined by the subscript(s). If > the > path cannot be followed to its end for any individual value (e.g. > <literal>val['a']['b']['c']</literal> where <literal>val['a']</literal> or > <literal>val['b']</literal> is null, a string, or a number), an error is > raised even if other values do conform. > </para> > <para> > An example of subscripting syntax: > +1 Pavel
