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: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Amit Langote <amitlangote09@gmail.com>, Erik Rijkers <er@xs4all.nl>, jian he <jian.universality@gmail.com>, Andres Freund <andres@anarazel.de>, Andrew Dunstan <andrew@dunslane.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2024-03-07T14:14:15Z
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.

On 2024-Mar-07, Tomas Vondra wrote:

> I was experimenting with the v42 patches, and I think the handling of ON
> EMPTY / ON ERROR clauses may need some improvement.

Well, the 2023 standard says things like

<JSON value function> ::=
  JSON_VALUE <left paren>
      <JSON API common syntax>
      [ <JSON returning clause> ]
      [ <JSON value empty behavior> ON EMPTY ]
      [ <JSON value error behavior> ON ERROR ]
  <right paren>

which implies that if you specify it the other way around, it's a syntax
error.

> I'm not sure what the SQL standard says about this, but it seems other
> databases don't agree on the order. Is there a particular reason to
> not allow both orderings?

I vaguely recall that trying to also support the other ordering leads to
having more rules.  Now maybe we do want that because of compatibility
with other DBMSs, but frankly at this stage I wouldn't bother.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"I am amazed at [the pgsql-sql] mailing list for the wonderful support, and
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