Horton

Re: Schema variables - new implementation for Postgres 15

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, Joel Jacobson <joel@compiler.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-01-25T08:52:48Z
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. Allow underscores in integer and numeric constants.

  2. Remove special outfuncs/readfuncs handling of RangeVar.catalogname.

  3. Remove extra space from dumped ALTER DEFAULT PRIVILEGES.

  4. Create FKs properly when attaching table as partition

  5. psql: improve tab-complete's handling of variant SQL names.

út 25. 1. 2022 v 9:48 odesílatel Julien Rouhaud <rjuju123@gmail.com> napsal:

> Hi,
>
> On Tue, Jan 25, 2022 at 09:35:09AM +0100, Pavel Stehule wrote:
> > út 25. 1. 2022 v 6:18 odesílatel Julien Rouhaud <rjuju123@gmail.com>
> napsal:
> >
> > > I think the lock should be
> > > acquired during IdentifyVariable.  It should probably be optional as
> one
> > > codepath only needs the information to raise a warning when a variable
> is
> > > shadowed, so a concurrent drop isn't a problem there.
> > >
> >
> > There is a problem, because before the IdentifyVariable call I don't know
> > if the variable will be shadowed or not.
> >
> > If I lock a variable inside IdentifyVariable, then I need to remember if
> I
> > did lock there, or if the variable was locked already, and If the
> variable
> > is shadowed and if lock is fresh, then I can unlock the variable.
>
> But in transformColumnRef() you already know if you found a matching
> column or
> not when calling IdentifyVariable(), so you know if an existing variable
> will
> shadow it right?
>

yes, you have true,

Thank you



>
> Couldn't you call something like
>
>     lockit = node == NULL;
>         varid = IdentifyVariable(cref->fields, &attrname, &not_unique,
> lockit);
>
> The only other caller is transformLetStmt(), which should always lock the
> variable anyway.
>