Re: [Q] Gupta & Oracle 7

In article <D12BE9.IAH_at_lanier.com>, dvick_at_lanier.com (Don Vick) says:
>
>In article <199412161124.AA06730_at_impar.aiva.lt>, <yuri_at_impar.aiva.lt> wrote:
>>îi!
>> Working with GUPTA SQLWindows 5.0 and ORACLE 7.013 we found it difficult
>> to realize on-line mode in our applications.
>>
>> Let's say, there are several users working on their clients' PCs with
>> SQLWindows created applications; all of them use the same ORACLE database.
>> If one of those users changes database, rest of them must immediately see
>> result of this modification on their screens.
>>
>> So, as I understand, we are to write some ORACLE trigger to enforce
>> server to send messages (containing information about changed item)
>> to every clients' PC every time the DB has been modified.
>>
>> How can we do that ? Would you be so kind to send some information,
>> example ?
>>

You might try creating a table that stores 1 record for each table in your system that you need to know this information about. The record would contain the table name and the last modified date/time. Add a trigger that would update this new table every time one of your other tables is modified in any way. Your clients would then periodically query Oracle for the last changed date/time of the table they are interested in by looking at this table (A rather short, small query). If the date/time is later than the one the app stored the last time it did this, then it reselects the data from the table it is interested in.

Timers would need to be used in SQLWindows to regularly query Oracle.

This still does not allow a true event-driven response to new data and clogs up the network with wasted requests. It does prevent you from selecting a large amount of data repeatedly and further hogging network bandwidth.

Merry Christmas,

J. Qualls Received on Tue Dec 20 1994 - 15:56:32 CET