MS SQL 7.0 HANGS

Issue--
We are experiencing apparent server hangs. Microsoft has traced the
problem to a complex query that is being run that uses parallelism and the
result set is being processed slowly (one row every 500 ms or so) The total
wall time that the query is open could be in excess of 30 minutes.
Facts--
MS SQL 7.0 allocates various resources, including memory for running
queries. This amount of memory is not user configurable and is based on
total memory in the server.
Complex queries, especially where the query plan indicates parallelism,
can use up a substantial amount of these resources.
If a complex query result is open without leaving sufficient resources
for other queries MS SQL 7.0 will not be able to process additional queries.
The server will appear "hung" to users until the complex query result set is
processed and closed.
Microsoft does not believe this is a flaw in MS SQL 7.0. We strongly
believe this is a serious bug.
These complex queries were not a problem under MS SQL 6.5 because of
it's simpler query engine
Microsoft claims the problem is "poorly written queries". We believe no
user query, no matter how poorly written, should be able to "hang" an
enterprise class database server (if that's what you consider MS SQL
Server). We would expect results like this from MS Access, not from MS SQL
server.
Discussion--
Is this a bug?
Please try to use OPTION (MAXDOP 1)
This helps you to use a single processor.
Sometimes parallelism does not give advantages on SQL7...
Think also that when using parallelism the indexes and joins are performed
differently allocating a lot of memory and scanning a lot of tables.
The best way to check this query is to look into the execution plan for a
"TOP 1" query; then the execution plan for the query without TOP.
"An Unhappy Microsoft Customer" <unhappy@.microsoft.com> wrote in message
news:930607826.300.90@.news.remarQ.com...
> Issue--
> We are experiencing apparent server hangs. Microsoft has traced the
> problem to a complex query that is being run that uses parallelism and the
> result set is being processed slowly (one row every 500 ms or so) The
total
> wall time that the query is open could be in excess of 30 minutes.
> Facts--
> MS SQL 7.0 allocates various resources, including memory for running
> queries. This amount of memory is not user configurable and is based on
> total memory in the server.
> Complex queries, especially where the query plan indicates
parallelism,
> can use up a substantial amount of these resources.
> If a complex query result is open without leaving sufficient resources
> for other queries MS SQL 7.0 will not be able to process additional
queries.
> The server will appear "hung" to users until the complex query result set
is
> processed and closed.
> Microsoft does not believe this is a flaw in MS SQL 7.0. We strongly
> believe this is a serious bug.
> These complex queries were not a problem under MS SQL 6.5 because of
> it's simpler query engine
> Microsoft claims the problem is "poorly written queries". We believe
no
> user query, no matter how poorly written, should be able to "hang" an
> enterprise class database server (if that's what you consider MS SQL
> Server). We would expect results like this from MS Access, not from MS
SQL
> server.
> Discussion--
> Is this a bug?
>
>
|||"Adriano Trevisan" <trevisan.adriano_at_tin.it> wrote in message news:<eu1D55zXEHA.2816@.TK2MSFTNGP11.phx.gbl>...
> Please try to use OPTION (MAXDOP 1)
> This helps you to use a single processor.
> Sometimes parallelism does not give advantages on SQL7...
>
[][vbcol=seagreen]
> no
> SQL
Why are you responding to a message dated in the last millenium (1999)?
Why cross post this to the ORACLE groups?
(note ORACLE group removed from my post)