Re: Oracle SQL Cancel
Date: 1996/10/26
Message-ID: <3272BEE0.76FE_at_mysite.com>#1/1
Tim Nickason wrote:
> We are currently use Oracle 7.3 on Dec Alpha Unix. To access the
> database we use a olap query tool called Dss Agent. We are experiencing
> a problem in that when users try to cancel a query (in Dss Agent). The
> Oracle database does not seem to heed. To make a long story short...
> Microstrategy claims the problem is that Oracle doe nor support
> SQL Cancel.
>
> Question: What is SQL Cancel? Is it an ODBC call?
Tim,
I'm not a programmer, but the problem you mention occurs with every
query tool that talks to Oracle via SQL*Net. What you're looking for is
often referred to as "asynchronous cancellation". The problem with
SQL*Net to date is its synchronous nature: Once a query has been sent
off to the server, there can be no further communication between the
client and Oracle until the SELECT has completed -- at which time
control is returned to the client. This also means that the client
cannot send a 'cancel' to the server before the query has completed
processing. It is also the reason for the infamous "locked PC" while
queries are processing -- the only solution for which is the '3-fingered
salute' (reboot).
As I understand it, this is primarily a function of the API (middleware) being used -- SQL*Net in this case. Other APIs, like Sybase/MS DBLIB, do permit cancellation. Furthermore, I understand that the new version of SQL*Net (2.1?) does permit asynch cancellation -- but many query tools still won't support it until they've been modified to allow cancels with Oracle.
Am sure there are more technical readers that can clarify the specifics better than I can, but this is basically the situation.
Rob Vonderhaar
Speedware Corporation
Reston, VA
Received on Sat Oct 26 1996 - 00:00:00 CEST