Re: PostgreSQL 8.0 Feature List?

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От Dave Cramer
Тема Re: PostgreSQL 8.0 Feature List?
Дата
Msg-id 1092661963.1550.74.camel@localhost.localdomain
обсуждение исходный текст
Ответ на Re: PostgreSQL 8.0 Feature List?  (Richard Welty <rwelty@averillpark.net>)
Ответы Re: PostgreSQL 8.0 Feature List?  (Thomas Hallgren <thhal@mailblocks.com>)
Список pgsql-general
Richard,

Actually, I think you will find that current implementations of java
will actually take

String foo = "Hello " + "World" and rewrite it into

String foo = new StringBuffer("Hello").append("World").toString()

But your point is still valid.

Dave
On Sat, 2004-08-14 at 14:27, Richard Welty wrote:
> On Sat, 14 Aug 2004 12:03:21 -0400 Jan Wieck <JanWieck@Yahoo.com> wrote:
>
> > On 8/12/2004 8:53 PM, Richard Welty wrote:
>
> > > On Thu, 12 Aug 2004 14:36:13 -0400 Vivek Khera <khera@kcilink.com> wrote:
> > >> >>>>> "RW" == Richard Welty <rwelty@averillpark.net> writes:
> > >> RW> i'm quite experienced in C and Java, so it's going to be in one of
> > >> RW> those two.  any comments from anyone on the language choice?
> > >
> > >> eRServer is written in Java.  It sucks up about 200Mb+ virtual memory
> > >> for a teeny-tiny little database.  I'd avoid java :-)
> > >
> > > java often sucks up too much memory. java doesn't have to suck
> > > up too much memory, it just usually gets written that way.
>
> > Right. The garbage collection automatically taking care of unreferenced
> > objects as a stop-gap for resource leakage is abused by lazy programmers
> > as a general purpose cleanup mechanism.
>
> some of it is this, certainly. some of it is bad education.
>
> i was a professional lisp programmer for some 10+ years. lisp, of
> course, has the ancestral garbage collection scheme, and the
> lisp garbage collectors at this juncture are very, very, very good,
> much more mature than java's garbage collector. nonetheless,
> lisp programmers who understand what is going on are exceedingly
> careful not to taunt the garbage collector if they want their app to
> go fast.
>
> the authors of 98%-99% of all introductory java textbooks have
> a lot to answer for. my favorite example of the lot is that
> they all teach programmers to use String in the following manner:
>
>    String query
>      = "SELECT foo "
>      + "FROM bar "
>      + "WHERE baz = 'bletch';"
>
>    return query;
>
> nowhere do these books ever mention StringBuffer. now java
> programmers who have developed a sufficient clue set know that
> String is hopelessly inefficient and will instead write the much
> preferable:
>
>    StringBuffer query = new StringBuffer();
>
>    query.append( "SELECT foo ");
>    query.append( "FROM bar ");
>    query.append( "WHERE baz = 'bletch';"
>
>    return new String( query);
>
> which not only is much more efficient, but Does Not
> Taunt The Garbage Collector.
>
> i kind of like _Practical Java_ (Peter Haggar, Addison Wesley)
> for its coverage of these details, as well as _Bitter Java_
> (Bruce Tate, Manning) for its discussion of how naive programmers
> writing Java web apps can (and often do) go seriously wrong
> (it talks a lot about efficient use of database backends, providing
> relevance to PostgreSQL and this mailing list.)
>
> richard
--
Dave Cramer
519 939 0336
ICQ # 14675561


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