Re: [BUGS] BUG #2114: (patch) COPY FROM ... end of

[Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>]

pgman wrote:
> Luke Lonergan wrote:
> > Bruce,
> > 
> > On 12/27/05 10:20 AM, "Bruce Momjian" <pgman(at)candle(dot)pha(dot)pa(dot)us> wrote:
> > 
> > > OK, original patch applied to HEAD and smaller version to 8.1.X, and
> > > regression test added, now attached.
> > 
> > Great, good catch.
> > 
> > Have you tested performance, before and after?
> > 
> > The only good way to test performance is using a fast enough I/O subsystem
> > that you are CPU-bound, which means >60MB/s of write speed.
> > 
> > I'd be happy to get you an account on one.
> 
> I don't need to test performance because it is the same code, just with
> macros and the two functions merged.  I do have an optimization for that
> loop but I saw no improvement so I didn't apply it.  It was basically to
> advance the pointer in a tight look just checking for \r, \n, and \\,
> but it seems the larger loop isn't much slower than a tight one.

Here is the patch I was testing.  I don't see any win on my hardware,
but it isn't a huge machine, so you might see an improvement on your
hardware, and if you do, we can consider applying it.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman(at)candle(dot)pha(dot)pa(dot)us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Index: src/backend/commands/copy.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/commands/copy.c,v
retrieving revision 1.257
diff -c -c -r1.257 copy.c
*** src/backend/commands/copy.c	28 Dec 2005 03:25:32 -0000	1.257
--- src/backend/commands/copy.c	28 Dec 2005 03:39:42 -0000
***************
*** 2207,2212 ****
--- 2207,2224 ----
  			need_data = false;
  		}
  
+ 		if (!cstate->encoding_embeds_ascii && !cstate->csv_mode)
+ 		{
+ 			char *p = copy_raw_buf + raw_buf_ptr;
+ 			char *e = copy_raw_buf + copy_buf_len;
+ 
+ 			while (p < e && *p != '\r' && *p != '\n' && *p != '\\')
+ 				p++;
+ 			prev_raw_ptr = raw_buf_ptr = p - copy_raw_buf;
+ 			IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(0);
+ 			IF_NEED_REFILL_AND_EOF_BREAK(0);
+ 		}
+ 				
  		/* OK to fetch a character */
  		prev_raw_ptr = raw_buf_ptr;
  		c = copy_raw_buf[raw_buf_ptr++];