Horton

Re: SQL/JSON features for v15

Andrew Dunstan <andrew@dunslane.net>

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From: Andrew Dunstan <andrew@dunslane.net>
To: Nikita Glukhov <n.gluhov@postgrespro.ru>, "Jonathan S. Katz" <jkatz@postgresql.org>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Michael Paquier <michael@paquier.xyz>, John Naylor <john.naylor@enterprisedb.com>, Amit Langote <amitlangote09@gmail.com>
Date: 2022-08-26T20:36:34Z
Lists: pgsql-hackers 
On 2022-08-26 Fr 16:11, Nikita Glukhov wrote:
>
> Hi,
>
> On 26.08.2022 22:25, Andrew Dunstan wrote:
>> On 2022-08-24 We 20:05, Nikita Glukhov wrote:
>>> v8 - is a highly WIP patch, which I failed to finish today.
>>> Even some test cases fail now, and they simply show unfinished
>>> things like casts to bytea (they can be simply removed) and missing
>>> safe input functions.
>> Thanks for your work, please keep going.
> I have completed in v9 all the things I previously planned:
>
>  - Added missing safe I/O and type conversion functions for 
>    datetime, float4, varchar, bpchar.  This introduces a lot 
>    of boilerplate code for returning errors and also maybe 
>    adds some overhead.
>
>  - Added JSON_QUERY coercion to UTF8 bytea using pg_convert_to().
>
>  - Added immutability checks that were missed with elimination 
>    of coercion expressions.  
>    Coercions text::datetime, datetime1::datetime2 and even 
>    datetime::text for some datetime types are mutable.
>    datetime::text can be made immutable by passing ISO date 
>    style into output functions (like in jsonpath).
>
>  - Disabled non-Const expressions in DEFAULT ON EMPTY in non 
>    ERROR ON ERROR case.  Non-constant expressions are tried to 
>    evaluate into Const directly inside transformExpr().
>    Maybe it would be better to simply remove DEFAULT ON EMPTY.


Yes, I think that's what I suggested upthread. I don't think DEFAULT ON
EMPTY matters that much, and we can revisit it for release 16. If it's
simpler please do it that way.


>
>
> It is possible to easily split this patch into several subpatches, 
> I will do it if needed.


Thanks, probably a good idea but I will start reviewing what you have
now. Andres and others please chime in if you can.


cheers


andrew


--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Commits

  1. JSON_TABLE: Add support for NESTED paths and columns

  2. Add basic JSON_TABLE() functionality

  3. Add SQL/JSON query functions

  4. Add soft error handling to some expression nodes

  5. Adjust populate_record_field() to handle errors softly

  6. Refactor code used by jsonpath executor to fetch variables

  7. Add more SQL/JSON constructor functions

  8. SQL/JSON: support the IS JSON predicate

  9. SQL/JSON: add standard JSON constructor functions

  10. Revert SQL/JSON features

  11. Numeric error suppression in jsonpath