Nikita, thank you!
I noticed another thing. 3-arguments version of functions
jsonpath_exists(), jsonpath_predicate(), jsonpath_query(),
jsonpath_query_wrapped() are:
1) Not documented
2) Not used in operator definitions
3) Not used in subsequent patches
So, it looks like we can just remove then. But I think we're very
likely can commit jsonpath patch to PostgreSQL 12, but I'm not sure
about other patches. So, having those functions exposed to user can
be extremely useful until we have separate nodes for SQL/JSON. So, I
vote to document these functions.
------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company