From: Ellen K. 

ADO.NET has automatic connection pooling.

On Fri, 20 May 2005 14:28:15 +0100, Adam
 wrote in message
:

>Paul Ranson wrote:
>
>> So your code has to check the connection before every call?
>
>Depends. No you don't have to. You can simply call to a pooled
>connection & it will give you one from it's hashtable of conns when you
>need it.
>
>It's an architectural issue as you could simply use some form of ORM
>instead (e.g. hibernate or JORM). If you want to get ambitious try:
>
>http://c-jdbc.objectweb.org/
>
>It is in C++ too given you have to write a class which instantiates the
>conn & then closes/destructs it when the class has been finished with.
>Do you keep that class around & if so how does it deal with network/db
>errors etc i.e. re-opening dead conns? Do you create the connection
>everytime & in a multithreaded/multi-user env do you then run out of db
>handles?
>
>Gee it sounds to me like you'd need to arch the solution dependant upon
>the use. Gosh that sounds similar....
>
>> How does the
>> pool determine that the connection is not active?
>>
>
>All sorts of ways. An oft used method is to use a factory method to get
>a conn & within the call to get the object from the factory you provide
>an expiry time. There can be an upper limit config'ed into the pool by
>the server admin i.e. you might set 10 minutes expiry but the server
>might go "sod that mate you're getting 18K milliseconds tops".
>
>
>> Seems like  you're leaping through hoops to avoid doing it the easy way.
>>
>
>Hardly. So are you keeping your object around & what happens if the db
>refuses/network is down/slow etc.? Having to jump through hoops in
>designing your class to guard against such occurences or simply create a
>new connection every time you access the db?
>
>Gee seems to me that you should just get a pooling mech as that's the
>easy way.
>
>
>> So why does Java not have destructors?
>
>You can (& should) close connections.
>
>> Somebody must be able to say. I think
>> it is because the original designers hadn't considered them in any other
>> context than memory management. And now they're stuck...
>>
>
>Hardly. No reason at all why you can't deference an object & then call
>system.gc() or indeed for something like a dbconn you can call conn.close().
>
>
>Adam

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