Horton

Re: [HACKERS] [PATCH] Generic type subscripting

Dmitry Dolgov <9erthalion6@gmail.com>

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From: Dmitry Dolgov <9erthalion6@gmail.com>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Dian M Fay <dian.m.fay@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, Alexander Korotkov <aekorotkov@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, David Steele <david@pgmasters.net>, Nikita Glukhov <n.gluhov@postgrespro.ru>, Alvaro Herrera <alvherre@2ndquadrant.com>, David Fetter <david@fetter.org>, Thomas Munro <thomas.munro@gmail.com>, Oleksandr Shulgin <oleksandr.shulgin@zalando.de>, Robert Haas <robertmhaas@gmail.com>, Michael Paquier <michael.paquier@gmail.com>, Oleg Bartunov <obartunov@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2021-01-14T15:04:54Z
Lists: pgsql-hackers 
> On Tue, Jan 12, 2021 at 08:02:59PM +0100, Pavel Stehule wrote:
> ne 10. 1. 2021 v 19:52 odesílatel Pavel Stehule <pavel.stehule@gmail.com>
> napsal:
>
> I tested behaviour and I didn't find anything other than the mentioned
> issue.
>
> Now I can check this feature from plpgsql, and it is working. Because there
> is no special support in plpgsql runtime, the update of jsonb is
> significantly slower than in update of arrays, and looks so update of jsonb
> has O(N2) cost. I don't think it is important at this moment - more
> important is fact, so I didn't find any memory problems.

Thanks for testing. Regarding updates when the structure doesn't match
provided path as I've mentioned I don't have strong preferences, but on
the second though probably more inclined for returning an error in this
case. Since there are pros and cons for both suggestions, it could be
decided by vote majority between no update (Dian) or an error (Pavel,
me) options. Any +1 to one of the options from others?

Other than that, since I've already posted the patch for returning an
error option, it seems that the only thing left is to decide with which
version to go.

Commits

  1. Throw error when assigning jsonb scalar instead of a composite object

  2. Filling array gaps during jsonb subscripting

  3. Implementation of subscripting for jsonb

  4. Allow ALTER TYPE to update an existing type's typsubscript value.

  5. Allow subscripting of hstore values.

  6. Support subscripting of arbitrary types, not only arrays.

  7. jit: Reference function pointer types via llvmjit_types.c.

  8. Teach contain_leaked_vars that assignment SubscriptingRefs are leaky.

  9. jit: Correct parameter type for generated expression evaluation functions.

  10. Renaming for new subscripting mechanism

  11. Fix assertion failure for SSL connections.

  12. Teach eval_const_expressions() to handle some more cases.