Horton

Re: remaining sql/json patches

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Amit Langote <amitlangote09@gmail.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2023-07-07T12:28:20Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. SQL/JSON: Various improvements to SQL/JSON query function docs

  2. SQL/JSON: Fix some obsolete comments.

  3. SQL/JSON: Fix issues with DEFAULT .. ON ERROR / EMPTY

  4. JSON_TABLE: Add support for NESTED paths and columns

  5. Fix JsonExpr deparsing to emit QUOTES and WRAPPER correctly

  6. Fix typo introduced in 6185c9737

  7. Add basic JSON_TABLE() functionality

  8. Avoid splitting errmsg string to span multiple lines

  9. Add SQL/JSON query functions

  10. Implement various jsonpath methods

  11. Add soft error handling to some expression nodes

  12. Adjust populate_record_field() to handle errors softly

  13. Refactor code used by jsonpath executor to fetch variables

  14. Test EXPLAIN (FORMAT JSON) ... XMLTABLE

  15. Simplify productions for FORMAT JSON [ ENCODING name ]

  16. Add trailing commas to enum definitions

  17. doc: add missing <returnvalue> and whitespace

  18. Add more SQL/JSON constructor functions

  19. Rename a nonterminal used in SQL/JSON grammar

  20. Some refactoring to export json(b) conversion functions

  21. Don't include CaseTestExpr in JsonValueExpr.formatted_expr

  22. Code review for commit b6e1157e7d

  23. Pass constructName to transformJsonValueExpr()

  24. Unify JSON categorize type API and export for external use

  25. Make some indentation in gram.y consistent

  26. Allow most keywords to be used as column labels without requiring AS.

  27. Reduce size of backend scanner's tables.

  28. Use perfect hashing, instead of binary search, for keyword lookup.

Looking at 0001 now.

I noticed that it adds JSON, JSON_SCALAR and JSON_SERIALIZE as reserved
keywords to doc/src/sgml/keywords/sql2016-02-reserved.txt; but those
keywords do not appear in the 2016 standard as reserved.  I see that
those keywords appear as reserved in sql2023-02-reserved.txt, so I
suppose you're covered as far as that goes; you don't need to patch
sql2016, and indeed that's the wrong thing to do.

I see that you add json_returning_clause_opt, but we already have
json_output_clause_opt.  Shouldn't these two be one and the same?
I think the new name is more sensible than the old one, since the
governing keyword is RETURNING; I suppose naming it "output" comes from
the fact that the standard calls this <JSON output clause>.

typo "requeted"

I'm not in love with the fact that JSON and JSONB have pretty much
parallel type categorizing functionality. It seems entirely artificial.
Maybe this didn't matter when these were contained inside each .c file
and nobody else had to deal with that, but I think it's not good to make
this an exported concept.  Is it possible to do away with that?  I mean,
reduce both to a single categorization enum, and a single categorization
API.  Here you have to cast the enum value to int in order to make
ExecInitExprRec work, and that seems a bit lame; moreso when the
"is_jsonb" is determined separately (cf. ExecEvalJsonConstructor)

In the 2023 standard, JSON_SCALAR is just

<JSON scalar> ::= JSON_SCALAR <left paren> <value expression> <right paren>

but we seem to have added a <JSON output format> clause to it.  Should
we really?

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"Entristecido, Wutra                     (canción de Las Barreras)
echa a Freyr a rodar
y a nosotros al mar"