Re: [HACKERS] "Adding missing from clause" (replacement) - Mailing list pgsql-patches

I have applied the following patch, which does make a few adjustments.

I called the variable add_missing_from, rather than
enable_implicit_from.  The former seemed clearer.

I also enhanced the documentation for the item.

I added comments for the End-of-list records.

Does someone want to make an argument that this variable should default
to false rather than true, for standards compliance?

---------------------------------------------------------------------------

Nigel J. Andrews wrote:
> On Thu, 1 May 2003, Tom Lane wrote:
>
> > "Nigel J. Andrews" <nandrews@investsystems.co.uk> writes:
> > > * Add enable_implicited_join GUC, defaulting to true. Emit notice if
> > > enabled, throw error if disabled when adding implicit RTE.
> >
> > I'd call it "enable_implicit_from", I think, but otherwise this seems
> > reasonable...
>
> Fair enough, I'm not particularly sold on my choice so here's a replacement
> patch with the GUC name changed. If there's a problem it'll probably be because
> I edited the patch and not the source.
>
> Log:
>
> * Add enable_implicit_from GUC, defaulting to true. Emit notice if
>   enabled, throw error if disabled when adding implicit RTE.
>
>
> --
> Nigel J. Andrews
>
>
> ---------------------------(end of broadcast)---------------------------
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--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073
Index: doc/src/sgml/runtime.sgml
===================================================================
RCS file: /cvsroot/pgsql-server/doc/src/sgml/runtime.sgml,v
retrieving revision 1.183
diff -c -c -r1.183 runtime.sgml
*** doc/src/sgml/runtime.sgml    11 Jun 2003 18:01:13 -0000    1.183
--- doc/src/sgml/runtime.sgml    11 Jun 2003 20:54:40 -0000
***************
*** 1300,1305 ****
--- 1300,1321 ----

      <variablelist>
       <varlistentry>
+       <term><varname>ADD_MISSING_FROM</varname> (<type>boolean</type>)</term>
+       <listitem>
+        <para>
+         This parameter controls whether a relation referenced in a query but
+         missing from the FROM clause should be automatically added to
+         the FROM clause. If enabled (the default), the notice
+         <literal>Adding missing FROM-clause entry for table "tablename"</literal>
+         is generated if a relation is automatically added. If not enabled,
+         an error is raised when an additional extra relation is required.
+         For SQL standards compliance, this value should be set to
+         <literal>false</>.
+        </para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry>
        <term><varname>AUSTRALIAN_TIMEZONES</varname> (<type>boolean</type>)</term>
        <indexterm><primary>Australian time zones</></>
        <listitem>
Index: src/backend/parser/parse_relation.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/parser/parse_relation.c,v
retrieving revision 1.81
diff -c -c -r1.81 parse_relation.c
*** src/backend/parser/parse_relation.c    29 Apr 2003 22:13:10 -0000    1.81
--- src/backend/parser/parse_relation.c    11 Jun 2003 20:54:42 -0000
***************
*** 32,37 ****
--- 32,39 ----
  #include "utils/lsyscache.h"
  #include "utils/syscache.h"

+ /* GUC parameter */
+ bool add_missing_from;

  static Node *scanNameSpaceForRefname(ParseState *pstate, Node *nsnode,
                          const char *refname);
***************
*** 1861,1867 ****
          }
      }
      if (foundInFromCl)
!         elog(NOTICE, "Adding missing FROM-clause entry%s for table \"%s\"",
!              pstate->parentParseState != NULL ? " in subquery" : "",
!              relation->relname);
  }
--- 1863,1876 ----
          }
      }
      if (foundInFromCl)
!     {
!         if (add_missing_from)
!             elog(NOTICE, "Adding missing FROM-clause entry%s for table \"%s\"",
!                  pstate->parentParseState != NULL ? " in subquery" : "",
!                  relation->relname);
!         else
!             elog(ERROR, "Missing FROM-clause entry%s for table \"%s\"",
!                  pstate->parentParseState != NULL ? " in subquery" : "",
!                  relation->relname);
!     }
  }
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/utils/misc/guc.c,v
retrieving revision 1.130
diff -c -c -r1.130 guc.c
*** src/backend/utils/misc/guc.c    11 Jun 2003 18:49:00 -0000    1.130
--- src/backend/utils/misc/guc.c    11 Jun 2003 20:54:49 -0000
***************
*** 43,48 ****
--- 43,49 ----
  #include "optimizer/paths.h"
  #include "optimizer/prep.h"
  #include "parser/parse_expr.h"
+ #include "parser/parse_relation.h"
  #include "storage/fd.h"
  #include "storage/freespace.h"
  #include "storage/lock.h"
***************
*** 550,559 ****
          {"transaction_read_only", PGC_USERSET, GUC_NO_RESET_ALL}, &XactReadOnly,
          false, NULL, NULL
      },

      {
          {NULL, 0}, NULL, false, NULL, NULL
!     }
  };


--- 551,565 ----
          {"transaction_read_only", PGC_USERSET, GUC_NO_RESET_ALL}, &XactReadOnly,
          false, NULL, NULL
      },
+     {
+         {"add_missing_from", PGC_USERSET}, &add_missing_from,
+         true, NULL, NULL
+     },

+     /* End-of-list marker */
      {
          {NULL, 0}, NULL, false, NULL, NULL
!     },
  };


***************
*** 742,747 ****
--- 748,754 ----
          0, 0, INT_MAX / 1000, NULL, NULL
      },

+     /* End-of-list marker */
      {
          {NULL, 0}, NULL, 0, 0, 0, NULL, NULL
      }
***************
*** 784,789 ****
--- 791,797 ----
          0.5, 0.0, 1.0, assign_random_seed, show_random_seed
      },

+     /* End-of-list marker */
      {
          {NULL, 0}, NULL, 0.0, 0.0, 0.0, NULL, NULL
      }
***************
*** 946,951 ****
--- 954,960 ----
          XLOG_sync_method_default, assign_xlog_sync_method, NULL
      },

+     /* End-of-list marker */
      {
          {NULL, 0}, NULL, NULL, NULL, NULL
      }
Index: src/backend/utils/misc/postgresql.conf.sample
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/utils/misc/postgresql.conf.sample,v
retrieving revision 1.80
diff -c -c -r1.80 postgresql.conf.sample
*** src/backend/utils/misc/postgresql.conf.sample    11 Jun 2003 18:01:14 -0000    1.80
--- src/backend/utils/misc/postgresql.conf.sample    11 Jun 2003 20:54:49 -0000
***************
*** 208,210 ****
--- 208,211 ----
  #statement_timeout = 0        # 0 is disabled, in milliseconds
  #db_user_namespace = false
  #preload_libraries = ''
+ #add_missing_from = true
Index: src/bin/psql/tab-complete.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/bin/psql/tab-complete.c,v
retrieving revision 1.78
diff -c -c -r1.78 tab-complete.c
*** src/bin/psql/tab-complete.c    11 Jun 2003 18:01:14 -0000    1.78
--- src/bin/psql/tab-complete.c    11 Jun 2003 20:54:52 -0000
***************
*** 492,497 ****
--- 492,498 ----
           * the rest should match USERSET and possibly SUSET entries in
           * backend/utils/misc/guc.c.
           */
+         "add_missing_from",
          "australian_timezones",
          "client_encoding",
          "client_min_messages",
Index: src/include/parser/parse_relation.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/parser/parse_relation.h,v
retrieving revision 1.39
diff -c -c -r1.39 parse_relation.h
*** src/include/parser/parse_relation.h    4 Sep 2002 20:31:45 -0000    1.39
--- src/include/parser/parse_relation.h    11 Jun 2003 20:54:52 -0000
***************
*** 16,21 ****
--- 16,23 ----

  #include "parser/parse_node.h"

+ extern bool add_missing_from;
+
  extern RangeTblEntry *refnameRangeTblEntry(ParseState *pstate,
                       const char *schemaname,
                       const char *refname,