Re: [HACKERS] proposal: schema variables

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.

--
Gilles Darold
Consultant PostgreSQL
http://dalibo.com - http://dalibo.org