> On Wed, May 29, 2019 at 6:17 PM Pavel Stehule <pavel.steh...@gmail.com> wrote: > > st 29. 5. 2019 v 17:49 odesÃlatel Dmitry Dolgov <9erthali...@gmail.com> > napsal: >> >> Rebase after pg_indent. Besides, off the list there was a suggestion that >> this >> could be useful to accept more than one data type as a key for subscripting. >> E.g. for jsonb it probably makes sense to understand both a simple key name >> and >> jsonpath: >> >> jsonb['a'] and jsonb['$.a'] >> >> While to implement it can be technically relatively straightforward I guess, >> I >> wonder if there is any opinion about how valuable it could be and what it >> should looks like from the syntax point of view (since I believe a user needs >> to specify which type needs to be used). > > > It is difficult decision - possibility to use jsonpath looks great, but > necessity to cast every time is not friendly.
Thanks. Yes, I also wonder if it's possible to avoid type casting every time, but other ideas seems syntactically equally not friendly. > Probably there can be preferred type if subscripting is of unknown type. > There can be similar rules to function's parameters. > > so jsonb['a'] -- key > jsonb['$.a'] -- key > jsonb['$.a'::jsonpath'] -- json path > > but it can be source of bad issues - so I think we don't need this feature in > this moment. This feature can be implemented later, I think. Yeah, I agree it's something that looks like a good potential improvement, not now but in the future.
