"William Robertson" <william.robertson_at_bigfoot.com> wrote in message
news:1134603116.785969.94660_at_f14g2000cwb.googlegroups.com...
> William Robertson wrote:
>> Mark C. Stock wrote:
>> > "Jeremy" <jeremy0505_at_gmail.com> wrote in message
>> > news:MPG.1e0a0b70784541598a071_at_news.individual.net...
>> > > In article <1134550096.100826.241610_at_g14g2000cwa.googlegroups.com>,
>> > > sybrandb_at_yahoo.com says...
>> > >> Right now, your dbms_output is ending up in a 'black hole' (in
>> > >> reality
>> > >> the PGA), and this may cause your procedure to fail.
>> > >>
>> > >
>> > > Hi Sybrand, how may this cause the procedure to fail? I know that if
>> > > running the procedure in sqlplus the buffer may be exceeded causing
>> > > an
>> > > exception but my understanding (perhaps incorrect?) was that the
>> > > output
>> > > would simply be disregarded unless being run by a "dbms_output-aware"
>> > > tool?
>> > >
>> > > --
>> > >
>> > > jeremy
>> >
>> > if dbms_output is not initialized (with the dbms_output.enable
>> > procedure)
>> > the effect is minimal, but i believe there is some effect -- i think it
>> > was
>> > daniel morgan who posted a case in a recent thread
>> >
>> > think of dbms_output as half of an interprocess communication pipe --
>> > actually kind of like a spigot and a bucket. calls to put_line fill the
>> > bucket, if the spigot is open and a bucket has been placed under it.
>> > evidently, though (based on what i remember from daniel's post) there's
>> > a
>> > slight leak in the spigot. so any program that can call pl/sql can
>> > first
>> > open the spigot and later empty the bucket.
>> >
>>
>> Spigot? Bucket?
>>
>> Isn't the code for PUT_LINE just this:
>>
>> procedure put_line(a varchar2) is
>> begin
>> if enabled then
>> tmpbuf := tmpbuf || a;
>> new_line;
>> end if;
>> end;
>>
>> (plus a couple of pointless overloadings)
>>
>> So if enabled is false it does nothing, as you can surely test for
>> yourself in SQL*Plus.
>
> I forgot to mention, the above is from Oracle 7.2 which is the last
> release before they wrapped the source code. DBMS_OUTPUT was updated in
> 10gR2 and so might behave differently now, possibly even in the manner
> of a spigot/bucket arrangement. I very much doubt whether it changed in
> the intervening versions.
>
spigot = 'if enabled'
bucket = 'tmpbuf := tmpbuf||a;'
++ mcs
Received on Wed Dec 14 2005 - 17:41:40 CST
