Re: NOLOGGING option, or ?

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Luke Lonergan <llonergan(at)greenplum(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Alon Goldshuv <agoldshuv(at)greenplum(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: NOLOGGING option, or ?
Date: 2005-06-02 02:27:51
Message-ID: 200506020227.j522RpG22470@candle.pha.pa.us
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Luke Lonergan wrote:
>
> >
> > Yep, we would _love_ those improvements.
> >
>
> Coming soon, probably from the guy you've never heard of :-)

LOL

> >
> > I am confused why you are confused. :-)
> >
> > Uh, how do you do the escapes if you don't double the escape character
> > on input so you can distinguish a literal escape from one use to mark
> > special data like a literal delimiter or a null?
>
> Escape processing would proceed as before, but the semantics would change to
> allow the use of different characters as the escape character, in addition
> to the special characters for delimiter and newline. Also, escape
> processing would be "false" as the default, so that the only special
> characters by default would be the newline and delimiter characters.
>
> Also of importance is the specification of newline and delimiter as
> arbitrary double byte or 8-bit characters.

I am still confused how you have reliable, never-break semantics without
special escaping.

How do you distinguis an escape-delimiter used to escape a delimiter in
the data from a literal escape-delimiter in the data being loaded --- it
seems impossible to do.

The idea of allowing a different escape character is interesting,
however, and certainly possible. Right now we allow ESCAPE to be
changed only in CSV mode, but I suppose it is possible to allow it to be
changed in non-CSV mode as well.

Or are you saying there would be no escape at all. If you make '@' the
escape, you can't just say @n is a newline because you need to make '@'
output as '@@' so you can distinguish @-n from a newline.

--
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

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