Horton

Re: proposal: schema variables

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2017-11-02T15:49:20Z
Lists: pgsql-hackers, pgsql-performance

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Move WAL sequence code into its own file

  2. Add ExplainState argument to pg_plan_query() and planner().

  3. Don't include access/htup_details.h in executor/tuptable.h

  4. Refactor to avoid code duplication in transformPLAssignStmt.

  5. Avoid including commands/dbcommands.h in so many places

  6. Restrict psql meta-commands in plain-text dumps.

  7. Split func.sgml into more manageable pieces

  8. Fix squashing algorithm for query texts

  9. EXPLAIN: Always use two fractional digits for row counts.

  10. Preliminary refactoring of plpgsql expression construction.

  11. plpgsql: pure parser and reentrant scanner

  12. Add some sanity checks in executor for query ID reporting

  13. Fix misleading error message context

  14. Add macros for looping through a List without a ListCell.

2017-11-02 13:35 GMT+01:00 Robert Haas <robertmhaas@gmail.com>:

> On Thu, Oct 26, 2017 at 12:51 PM, Pavel Stehule <pavel.stehule@gmail.com>
> wrote:
> > The variables can be modified by SQL command SET (this is taken from
> > standard, and it natural)
> >
> > SET varname = expression;
>
> Overloading SET to handle both variables and GUCs seems likely to
> create problems, possibly including security problems.  For example,
> maybe a security-definer function could leave behind variables to
> trick the calling code into failing to set GUCs that it intended to
> set.  Or maybe creating a variable at the wrong time will just break
> things randomly.
>

The syntax CREATE OR REPLACE FUNCTION xxx $$ ... $$ SET GUC=, ... is always
related only to GUC. So there should not be any security risk.

It is another reason why GUC and variables should be separated.

I know so there is risk of possibility of collision. There are two
possibilities

a) use different keyword - but it is out of SQL/PSM and out of another
databases.

b) detect possible collision and raise error when assignment is ambiguous.
I am thinking about similar solution used in plpgsql, where is a
possibility of collision between SQL identifier and plpgsql variable.

Regards

Pavel




>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>