Horton

Re: [HACKERS] [PATCH] Generic type subscripting

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Pavel Stehule <pavel.stehule@gmail.com>, 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: 2020-12-07T22:17:08Z
Lists: pgsql-hackers 
Hi,

On 2020-12-07 16:32:32 -0500, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > I think it'd be a better to rely on the backend's definition of
> > ExecEvalBoolSubroutine etc. For the functions implementing expression
> > steps I've found that far easier to work with over time (because you can
> > get LLVM to issue type mismatch errors when the signature changes,
> > instead of seeing compile failures).
> 
> I'm a little unclear on what you mean here?  There wasn't such a
> thing as ExecEvalBoolSubroutine until I added it in this patch.

Basically that I suggest doing what I did in the prototype patch I
attached, mirroring what it did with TypeExecEvalSubroutine for the new
ExecEvalBoolSubroutine case.


> What did you think of the idea of merging EEOP_SBSREF_OLD / ASSIGN / FETCH
> into a single step type distinguished only by the callback function?

I don't have a strong opinion on this. I guess find it a bit easier to
understand the generated "program" if the opcodes are distinct (I've a
pending patch printing the opcode sequence). Especially as the payload
is just function pointers.

So I think I'd just merge the *implementation* of the steps, but leave
the different opcodes around?


Greetings,

Andres Freund

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.