Client/Server
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What are the issues to be considered in developing a database oriented client/server application. (like data transfers etc.)
1. Don't use Oracle 2. See 1. Christian We're just observing the seasonal migration from VB to VC. Most of these birds will be killed by predators or will die of hunger. Only the best will survive - Tomasz Sowinski 29-07-2002 ( on the number of newbie posters in the VC forum ) Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002
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1. Don't use Oracle 2. See 1. Christian We're just observing the seasonal migration from VB to VC. Most of these birds will be killed by predators or will die of hunger. Only the best will survive - Tomasz Sowinski 29-07-2002 ( on the number of newbie posters in the VC forum ) Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002
;P Funny...I don't know why i'm laughing, but it was still funny...however i'm curious as to why you'd say that...? Whats wrong with Oracle...? or were you being sarcastic...? just curious "An expert is someone who has made all the mistakes in his or her field" - Niels Bohr
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;P Funny...I don't know why i'm laughing, but it was still funny...however i'm curious as to why you'd say that...? Whats wrong with Oracle...? or were you being sarcastic...? just curious "An expert is someone who has made all the mistakes in his or her field" - Niels Bohr
Oracle is a consultant's dream. While you can install MS SQL Server and run it without making custom changes to its configuration, to reach decent Oracle performance you need to learn and learn and learn. But if your budget is good and you like challenges, Oracle is fine :) Vagif Abilov MCP (Visual C++) Oslo, Norway If you're in a war, instead of throwing a hand grenade at the enemy, throw one of those small pumpkins. Maybe it'll make everyone think how stupid war is, and while they are thinking, you can throw a real grenade at them. Jack Handey, Deep Thoughts
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;P Funny...I don't know why i'm laughing, but it was still funny...however i'm curious as to why you'd say that...? Whats wrong with Oracle...? or were you being sarcastic...? just curious "An expert is someone who has made all the mistakes in his or her field" - Niels Bohr
Most recent example. The OLE DB provider for Oracle leaks memory. We download a new one. 75 MEG later, I have a provider which STILL leaks memory, but now the full set of client tools will no longer run, I cannot view the database. I do an uninstall, then try to reinstall the client tools. It tells me it needs the migration wizard in order to install the client tools. I download 125 MEG of wizard ( which I have no use for ) and install them. Still insists I need the installation wizard to install the client tools. Manually uninstall the client tools ( there is nothing in the add/remove area to do this and the uninstaller from Oracle refuses to uninstall a lot of stuff ). Finally get the Client tools to install, using Custom and what is in the list of options ? The Migration Wizard. Do a full install, and all is OK with the Client Tools, but the OLE DB driver won't work. Uninstall and reinstall it three times. No go. Install the newer client tools which I had downloaded previously. Now the Client Tools no longer work. Literally a full work day doing this, and half a day trying to get help from the Oracle site. This is NOT an isolated incident. Christian We're just observing the seasonal migration from VB to VC. Most of these birds will be killed by predators or will die of hunger. Only the best will survive - Tomasz Sowinski 29-07-2002 ( on the number of newbie posters in the VC forum ) Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002
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Most recent example. The OLE DB provider for Oracle leaks memory. We download a new one. 75 MEG later, I have a provider which STILL leaks memory, but now the full set of client tools will no longer run, I cannot view the database. I do an uninstall, then try to reinstall the client tools. It tells me it needs the migration wizard in order to install the client tools. I download 125 MEG of wizard ( which I have no use for ) and install them. Still insists I need the installation wizard to install the client tools. Manually uninstall the client tools ( there is nothing in the add/remove area to do this and the uninstaller from Oracle refuses to uninstall a lot of stuff ). Finally get the Client tools to install, using Custom and what is in the list of options ? The Migration Wizard. Do a full install, and all is OK with the Client Tools, but the OLE DB driver won't work. Uninstall and reinstall it three times. No go. Install the newer client tools which I had downloaded previously. Now the Client Tools no longer work. Literally a full work day doing this, and half a day trying to get help from the Oracle site. This is NOT an isolated incident. Christian We're just observing the seasonal migration from VB to VC. Most of these birds will be killed by predators or will die of hunger. Only the best will survive - Tomasz Sowinski 29-07-2002 ( on the number of newbie posters in the VC forum ) Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002
I'm convinced... :) I've never used DB for applications, but only for developing more dynamic websites...I always thought mySQL was just dandy... :) "An expert is someone who has made all the mistakes in his or her field" - Niels Bohr
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I'm convinced... :) I've never used DB for applications, but only for developing more dynamic websites...I always thought mySQL was just dandy... :) "An expert is someone who has made all the mistakes in his or her field" - Niels Bohr
Hockey wrote: I've never used DB for applications, but only for developing more dynamic websites...I always thought mySQL was just dandy... Works for me! - Jason (SonorkID 100.611) The Code Project - Orange makes the art grow fonder
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What are the issues to be considered in developing a database oriented client/server application. (like data transfers etc.)
Here's some things to get you thinking, they're in no particular order of importance... 1) Something fairly important and often overlooked when moving from 2 tier (ie client accessing database directly) to n tier (ie client accesses servers that access database) models is that you cant just change your database calls to server calls and expect to have any performance. So, say you need to get a list of customer orders. In a 2 tier system the client might make call to the database to get a list of customers and then a call per customer to get each customer's orders, or whatever. This is a less than ideal design for 2 tier as you can most probably move a lot of the work into the db anyway, but for n tier it's a nightmare. You want one call from client to server that retrieves all of the information that you need in one hit... 2) Don't retain state in the server. Stateless is the way to go. Each call from the client should assume that the server has just been restarted and knows nothing about the client prior to the call. This helps with scaling out to server farms at a later date. 3) If you're doing 2 then you cant do this anyway, but, don't hold resources across client calls. So no server interfaces that look like LockThingy(), DoWorkWithMyThingy(), UnlockThingy()... 4) Try not to write your own middleware. There's plenty out there that works, just pick something. Simple TCP/IP byte stream command parsing is fine, but if you need complex load balancing or fail over then chances are someone else has already done it better than you can do it... 5) Only pull data to the client that you actually need. So, that list control that you want to populate with 200000 rows, so that the client can pick 1, just say no... 6) Speed up the server with caches if necessary (though you should trust your database first and only add cacheing to the server if your profiling shows that it's needed). Note this doesnt contradict 2 as the client shouldnt need to know or expect the caching to be there, things are just slightly faster if it is. 7) Pick appropriate technology. C++, VB, COM+, OLEDB? Java, CORBA, JDBC? Remember the client doesnt have to use the same technology as the server. Remember that some things work better on a corporate intranet than on the internet... 8) Get a thin thread of functionality from front to back as soon as possible. Dont spend 2 months writing a cool gui (because you know how to do that bit) and leave the connectivity and server till the end (because it cant be that hard). Get a dialog