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From: Bruce Momjian <pgman@candle.pha.pa.us>
Message-Id: <200302031402.h13E2gV26646@candle.pha.pa.us>
Subject: Re: MOVE LAST: why?
In-Reply-To: <16921.1042418690@sss.pgh.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 3 Feb 2003 09:02:41 -0500 (EST)
Cc: Hiroshi Inoue <Inoue@tpf.co.jp>, pgsql-hackers@postgresql.org
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The following patch removes FETCH LAST and instead supports FETCH ALL. 
It also clarifies the docs to mention it sits on the last row, not after
the last row.

Applied.

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

Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Hiroshi Inoue wrote:
> > Are you suggesting removing FETCH LAST _and_ MOVE LAST?. 
> >> 
> >> Yes. Should cursors be positioned on the last row
> >> or EOF by MOVE LAST ? Anyway I see no necessity to use
> >> the standard keyword LAST currently.
> >> 
> > I think MOVE LAST works well.
> 
> > OK, so we will switch it to MOVE END.  That seems OK.
> 
> What is good about that???  We already have a nonstandard keyword
> for this functionality: MOVE ALL.  There is no reason to invent another
> one.
> 
> I tend to agree with Hiroshi that it's a bad idea to add a standard
> keyword to represent not-quite-standard behavior.  MOVE ALL is our
> historical spelling for this functionality, and adding MOVE LAST is
> not really bringing anything to the party.
> 
> 			regards, tom lane
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
> 
> http://www.postgresql.org/users-lounge/docs/faq.html
> 

-- 
  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
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Index: doc/src/sgml/ref/fetch.sgml
===================================================================
RCS file: /cvsroot/pgsql-server/doc/src/sgml/ref/fetch.sgml,v
retrieving revision 1.23
diff -c -c -r1.23 fetch.sgml
*** doc/src/sgml/ref/fetch.sgml	8 Jan 2003 00:22:26 -0000	1.23
--- doc/src/sgml/ref/fetch.sgml	3 Feb 2003 14:00:38 -0000
***************
*** 22,28 ****
    </refsynopsisdivinfo>
    <synopsis>
  FETCH [ <replaceable class="PARAMETER">direction</replaceable> ] [ <replaceable class="PARAMETER">count</replaceable> ] { IN | FROM } <replaceable class="PARAMETER">cursor</replaceable>
! FETCH [ FORWARD | BACKWARD | RELATIVE ] [ <replaceable class="PARAMETER">#</replaceable> | ALL | LAST | NEXT | PRIOR ]
      { IN | FROM } <replaceable class="PARAMETER">cursor</replaceable>
    </synopsis>
  
--- 22,28 ----
    </refsynopsisdivinfo>
    <synopsis>
  FETCH [ <replaceable class="PARAMETER">direction</replaceable> ] [ <replaceable class="PARAMETER">count</replaceable> ] { IN | FROM } <replaceable class="PARAMETER">cursor</replaceable>
! FETCH [ FORWARD | BACKWARD | RELATIVE ] [ <replaceable class="PARAMETER">#</replaceable> | ALL | NEXT | PRIOR ]
      { IN | FROM } <replaceable class="PARAMETER">cursor</replaceable>
    </synopsis>
  
***************
*** 107,123 ****
  
  	 <varlistentry>
  	  <term>
- 	   LAST
- 	  </term>
- 	  <listitem>
- 	   <para>
- 	    Same as <literal>ALL</>, but conforms to SQL92 syntax.
- 	   </para>
- 	  </listitem>
- 	 </varlistentry>
- 
- 	 <varlistentry>
- 	  <term>
  	   NEXT
  	  </term>
  	  <listitem>
--- 107,112 ----
***************
*** 212,218 ****
     If the number of rows remaining in the cursor is less
     than <replaceable class="PARAMETER">#</replaceable>,
     then only those available are fetched.
!    Substituting the keyword ALL or LAST in place of a number will
     cause all remaining rows in the cursor to be retrieved.
     Rows may be fetched in both FORWARD and BACKWARD
     directions. The default direction is FORWARD.
--- 201,207 ----
     If the number of rows remaining in the cursor is less
     than <replaceable class="PARAMETER">#</replaceable>,
     then only those available are fetched.
!    Substituting the keyword ALL in place of a number will
     cause all remaining rows in the cursor to be retrieved.
     Rows may be fetched in both FORWARD and BACKWARD
     directions. The default direction is FORWARD.
***************
*** 220,232 ****
  
    <para>
     The cursor position can be before the first row of the query result, or on
!    any particular row of the result, or after the last row of the result.
     When created, a cursor is positioned before the first row.  After fetching
     some rows, the cursor is positioned on the last row retrieved.  A new
     <command>FETCH</command> always steps one row in the specified direction
     (if possible) before beginning to return rows.  If the
     <command>FETCH</command> requests more rows than available, the cursor is
!    left positioned after the last row of the query result (or before the first
     row, in the case of a backward fetch).  This will always be the case after
     <command>FETCH ALL</>.
    </para>
--- 209,221 ----
  
    <para>
     The cursor position can be before the first row of the query result, or on
!    any particular row of the result.
     When created, a cursor is positioned before the first row.  After fetching
     some rows, the cursor is positioned on the last row retrieved.  A new
     <command>FETCH</command> always steps one row in the specified direction
     (if possible) before beginning to return rows.  If the
     <command>FETCH</command> requests more rows than available, the cursor is
!    left positioned on the last row of the query result (or on the first
     row, in the case of a backward fetch).  This will always be the case after
     <command>FETCH ALL</>.
    </para>
***************
*** 236,242 ****
       A zero row count requests fetching the current row without moving the
       cursor --- that is, re-fetching the most recently fetched row.
       This will succeed unless the cursor is positioned before the
!      first row or after the last row; in which case, no row is returned.
      </para>
     </tip>
  
--- 225,231 ----
       A zero row count requests fetching the current row without moving the
       cursor --- that is, re-fetching the most recently fetched row.
       This will succeed unless the cursor is positioned before the
!      first row; in which case, no row is returned.
      </para>
     </tip>
  
Index: doc/src/sgml/ref/move.sgml
===================================================================
RCS file: /cvsroot/pgsql-server/doc/src/sgml/ref/move.sgml,v
retrieving revision 1.16
diff -c -c -r1.16 move.sgml
*** doc/src/sgml/ref/move.sgml	8 Jan 2003 00:22:26 -0000	1.16
--- doc/src/sgml/ref/move.sgml	3 Feb 2003 14:00:38 -0000
***************
*** 34,40 ****
    </title>
    <para>
     <command>MOVE</command> allows the user to move the cursor position a 
!    specified number of rows, or all the way to the end or start of the query.
     <command>MOVE</command> works exactly like the <command>FETCH</command>
     command, except it only repositions the cursor and does not return rows.
    </para>
--- 34,41 ----
    </title>
    <para>
     <command>MOVE</command> allows the user to move the cursor position a 
!    specified number of rows, or to the beginning or end of the cursor.
!    <command>MOVE ALL</command> moves to the last row of the cursor.
     <command>MOVE</command> works exactly like the <command>FETCH</command>
     command, except it only repositions the cursor and does not return rows.
    </para>
Index: src/backend/parser/gram.y
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/parser/gram.y,v
retrieving revision 2.397
diff -c -c -r2.397 gram.y
*** src/backend/parser/gram.y	2 Feb 2003 23:46:38 -0000	2.397
--- src/backend/parser/gram.y	3 Feb 2003 14:01:13 -0000
***************
*** 361,367 ****
  
  	KEY
  
! 	LANCOMPILER LANGUAGE LAST LEADING LEFT LEVEL LIKE LIMIT
  	LISTEN LOAD LOCAL LOCALTIME LOCALTIMESTAMP LOCATION
  	LOCK_P
  
--- 361,367 ----
  
  	KEY
  
! 	LANCOMPILER LANGUAGE LEADING LEFT LEVEL LIKE LIMIT
  	LISTEN LOAD LOCAL LOCALTIME LOCALTIMESTAMP LOCATION
  	LOCK_P
  
***************
*** 2713,2719 ****
  			Iconst									{ $$ = $1; }
  			| '-' Iconst							{ $$ = - $2; }
  			| ALL									{ $$ = INT_MAX; }
- 			| LAST									{ $$ = INT_MAX; }
  			| NEXT									{ $$ = 1; }
  			| PRIOR									{ $$ = -1; }
  		;
--- 2713,2718 ----
***************
*** 7131,7137 ****
  			| KEY
  			| LANCOMPILER
  			| LANGUAGE
- 			| LAST
  			| LEVEL
  			| LISTEN
  			| LOAD
--- 7130,7135 ----
Index: src/backend/parser/keywords.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/parser/keywords.c,v
retrieving revision 1.132
diff -c -c -r1.132 keywords.c
*** src/backend/parser/keywords.c	12 Dec 2002 20:35:13 -0000	1.132
--- src/backend/parser/keywords.c	3 Feb 2003 14:01:14 -0000
***************
*** 172,178 ****
  	{"key", KEY},
  	{"lancompiler", LANCOMPILER},
  	{"language", LANGUAGE},
- 	{"last", LAST},
  	{"leading", LEADING},
  	{"left", LEFT},
  	{"level", LEVEL},
--- 172,177 ----

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