direct mode limitations?

Discussion of open issues, suggestions and bugs regarding ODAC (Oracle Data Access Components) for Delphi, C++Builder, Lazarus (and FPC)
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Ludek
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Joined: Thu 12 Oct 2006 09:34

direct mode limitations?

Post by Ludek » Fri 28 May 2010 07:15

Hi, are there any known limitations in direct mode in comparison to client mode? My attempt to use torachangenotification in direct mode failed... is it not supported from odac or from oracle? are there more limitations?
Thanks.

bork
Devart Team
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Joined: Fri 12 Mar 2010 07:55

Post by bork » Fri 28 May 2010 09:18

Hello

You can find Direct mode limitation in the ODAC help in the section: Using ODAC -> Connecting in Direct Mode -> Comparison of Client mode vs. Direct mode.

Ludek
Posts: 301
Joined: Thu 12 Oct 2006 09:34

Post by Ludek » Mon 31 May 2010 07:38

Thanks

Ludek
Posts: 301
Joined: Thu 12 Oct 2006 09:34

Post by Ludek » Mon 31 May 2010 07:43

i've found following limitations:
Comparison of Client mode vs. Direct mode
Applications that use Client mode and those that use Direct mode have similar size and performance. The security of using the Direct mode is the same as using Client without Oracle Advanced Security. ODAC in Direct mode uses DES authentication and does not now support Oracle Advanced Security.
Advantages of using Direct mode
Installation and administration of Oracle client software are not required.
System requirements are reduced.
Direct mode limitations
Connect using TCP/IP protocol only
Some types are not available, like OBJECT, ARRAY, REF, XML, BINARY_DOUBLE, BINARY_FLOAT.
The RowsAffected property is not returned correctly for queries with RETURNING clause
TOraLoader direct loading is not supported.
Certain problems may occur when using firewalls.
Direct mode does not support NLS conversion on the client side.
Transparent Application Failover is not supported.
statement caching is not available.
OS authentication and changing expired passwords features are not available.
We do not guarantee stability of multithreaded applications. It is highly recommended to use separate TOraSession component for each thread when using ODAC from different threads.
Please note that we do not guarantee ODAC Direct mode compatibility with all Oracle servers and in every network. We have tested Direct mode for all versions of Oracle servers for Windows and Linux since 7.3 on a local network. Other platforms may cause some incompatibility issues.
Connecting in Direct mode is managed transparently by the TOraSession object, and you can easily return to connecting through OCI in Client mode at any time if restrictions above become critical for you.
but i can't see anything about change notification...?

bork
Devart Team
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Post by bork » Mon 31 May 2010 11:59

Please describe what does it mean: "change notification"?

Ludek
Posts: 301
Joined: Thu 12 Oct 2006 09:34

Post by Ludek » Mon 31 May 2010 12:03

the usage of TOraChangeNotification component :)

bork
Devart Team
Posts: 649
Joined: Fri 12 Mar 2010 07:55

Post by bork » Tue 01 Jun 2010 08:49

Thank you for the information. ODAC help will be updated in one of the next builds/versions of ODAC.

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