Con: "JSON path expression" is a recurring them in the *grammars* of user-facing operators in [1], [2], [3], and [4]. But it doesn't necessarily follow that the function implemented in Step 2 will provide useful infrastructure for PG's eventual implementations of "JSON_TABLE", etc.
We can implement subset only - our XPath based on libxml2 does it too. The good target is support of usual examples on the net.
Hi Pavel,
Can you clarify what you meant? I *think* you're saying:
* It's not important for me to match the syntax/semantics of the json-path implementations found in MySQL / Oracle / DB2 / MS SQL Server, and
* Instead, I should just use examples / explanations on the web as my guidance.