Re: [HACKERS] proposal: schema variables

2018-06-27 19:15 GMT+02:00 Gilles Darold <gilles(dot)darold(at)dalibo(dot)com>:

> Le 27/06/2018 à 13:22, Pavel Stehule a écrit :
>
> Hi
>
> 2018-06-27 12:21 GMT+02:00 Gilles Darold <gilles(dot)darold(at)dalibo(dot)com>:
>
>> Hi,
>>
>> I'm reviewing the patch as it was flagged in the current commit fest.
>> Here are my feedback:
>>
>> - The patch need to be rebased due to changes in file
>> src/sgml/catalogs.sgml
>>
>> - Some compilation warning must be fixed:
>>
>> analyze.c: In function ‘transformLetStmt’:
>> analyze.c:1568:17: warning: variable ‘rte’ set but not used
>> [-Wunused-but-set-variable]
>> RangeTblEntry *rte;
>> ^~~
>> tab-complete.c:1268:21: warning: initialization from incompatible pointer
>> type [-Wincompatible-pointer-types]
>> {"VARIABLE", NULL, &Query_for_list_of_variables},
>>
>> In the last warning a NULL is missing, should be written: {"VARIABLE",
>> NULL, NULL, &Query_for_list_of_variables},
>>
>>
>> - How about Peter's suggestion?:
>> "In DB2, the privileges for variables are named READ and WRITE. That
>> would make more sense to me than reusing the privilege names for tables.
>>
> The patch use SELECT and UPDATE which make sense too for SELECT but
>> less for UPDATE.
>>
>> - The implementation of "ALTER VARIABLE varname SET SCHEMA schema_name;"
>> is missing
>>
>> - ALTER VARIABLE var1 OWNER TO gilles; ok but not documented and missing
>> in regression test
>>
>> - ALTER VARIABLE var1 RENAME TO var2; ok but not documented and missing
>> in regression test
>>
>> More generally I think that some comments must be rewritten, especially
>> those talking about a PoC. In documentation there is HTML comments that can
>> be removed.
>>
>> Comment at end of file src/backend/commands/schemavar.c generate some
>> "indent with spaces" errors with git apply but perhaps the comment can be
>> entirely removed or undocumented details moved to the right place.
>>
>> Otherwise all regression tests passed without issue and especially your
>> new regression tests about schema variables.
>>
>> I have a patch rebased, let me known if you want me to post the new diff.
>>
>
> I plan significant refactoring of this patch for next commitfest. There
> was anotherstrong Peter's and Robert comments
>
> 1. The schema variables should to have own system table
> 2. The composite schema variables should to use explicitly defined
> composite type
> 3. The memory management is not nice - transactional drop table with
> content is implemented ugly.
>
> I hope, so I can start on these issues next month.
>
> Thank you for review - I'll recheck ALTER commands.
>
>>
>> Otherwise all regression tests passed without issue and especially your
>> new regression tests about schema variables.
>>
>> I have a patch rebased, let me known if you want me to post the new diff.
>>
>
> I plan significant refactoring of this patch for next commitfest. There
> was anotherstrong Peter's and Robert c
> Regards
>
>
> Ok Pavel, I've changed the status to "Waiting for authors" so that no one
> will make an other review until you send a new patch.
>
I am sending a new update of this feature. The functionality is +/- same
like previous patch, but a implementation is based on own catalog table.

I removed functions for manipulation with schema variables. These functions
can be added later simply. Now If we hold these functions, then we should
to solve often collision inside pg_proc.

Changes:

* own catalog - pg_variable
* the rights are renamed - READ|WRITE
* the code is cleaner

Regards

Pavel

>
> --
> Gilles Darold
> Consultant PostgreSQLhttp://dalibo.com - http://dalibo.org
>
>