Connect to multiple databases at one time?
goravanis at gmail.com
Thu Jan 20 15:05:51 UTC 2022
Thank you for your Most Learned and thoughtful response to my question. The presence of people like you answering questions is most valuable to the rest of us. I hope to become a learned consultant and EVENTUALLY get the kind of clients that would require me to understand and implement the types of things you discuss. I am worried that I will be kept down in the doldrums of dealing with very small mom and pop entities for some time.. and not ever be able to code for larger entities that need such performance management tricks implemented… I like the complex.. I kind of thrive where the mind is required to really strain to find solutions, and remember many important little tricks and techniques in order to gain the performance required, and to manage serious data handling, where precision in really required.. I hope to get to that point of success as a consultant. Omnis’s position as a rather "un used" product does not help me in this endeavor.. Clifford Ilkay once told me that it’s impossible to sell the idea of using Omnis to the corporate world.. while that is not entirely true.. there are some corporations using it.. it is largely true given that there is a serious lack of developers who know Omnis located around the world. For example, I am likely the only one in Orlando Florida, a rather large city. In all of Florida, a rather large state, there is likely only a few. I myself love Omnis, believe in it, plan to stick with it and use it for businesses needs, but it’s position in the marketplace sure does not help me. That is sad.
I do plan on having clients that require me to understand the implement the various types of App Server available for performance requirements. I also plan on using worker objects. Both of these so that one users generating of a report does not bog down all other users. That’s important even in smaller entities day to day operations. At this point I am simply STUDYING EVERYTHING so that I can know what is at my disposal, what I can offer, and how to do it. For a very long time, 28 years now, I have been dealing exclusively with a single user almost "entertainment" application.. for learning’s sake and other reasons I did put it to SQL.. I’m glad I got that learning curve handled.. that is, the "Omnis to SQL" parts of Omnis.. how do to SQL from Omnis and with Omnis.. In the late eighties I did do consulting with many newspapers and installed multi user Omnis applications that I wrote.. in many newspapers.. less than or around 5 users usually.. though sometimes more.. and that was easy.. back then it was all easy. I have that in my background. Now I am again studying multi user considerations, setting up Postgres, setting up VPS’s, encryption, SSL, and so on and so on.. many issues to deal with now.. trying to get up to speed on all these things so that I can begin with a first client.. which I don’t have yet.. just in the study phase.. collecting information on how to do all the standard things that I will have to handle.
That’s why your post back to me is so helpful.. you lightly touch on "things to remember and consider".. I appreciate that very much.
In my studies, I will use my own server as a test bed. You helped me set it up, more than any other single person for sure. It was you. I thank you.
I have REALLY discovered the ARCHIVES now. IT is a very valuable place to hang out when trying to learn Omnis and related matters. The search function is very sufficient for finding what you are looking for. 47 Thousand Posts Strong at this point.
> On Jan 20, 2022, at 4:22 AM, Sten-Erik Björling <s-e.bjorling at enviro.se> wrote:
> Hi Das,
> I use session pools for this and in the most extreme situations I use dynamic assignment of the DBs for the pools depending on the DB choice of the clients - demands generic SQL and no stored process etc. though…
> There are some advantages to session pools:
> - You can dedicate session pools for different purposes - read-only is one example that allows the DB to not involve costly record locking during access etc.
> - Session pools allows the number of connections to the DB to be kept down - good in more heavily used systems.
> - Session pools also allows for very compact programming and effective use of worker objects.
> The disadvantage at this point using session pools is if implementing the multi-core Omnis app server - will demand routines to keep the number of sessions available in the pool to a functional minimum.
> In both cases - utilise the Yield to other threads command at relevant sections of your code. One tick represents about 17 milliseconds and many searches and interactions with your database system delivers results to an app-server faster than that. Also in remote forms - set the maxPollDelay to 1 to trigger a fast refresh at the client side of the subform containing the data.
> Take care, all the best…
>> 19 jan. 2022 kl. 23:47 skrev Mike Matthews - Omnis via omnisdev-en <omnisdev-en at lists.omnis-dev.com>:
>> an you connect to multiple SQL databases at one time together?
>> Or only one at a time, and you switch back and forth to do multiple?
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