using encryption and compression

Discussion of open issues, suggestions and bugs regarding SDAC (SQL Server Data Access Components) for Delphi, C++Builder, Lazarus (and FPC)
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brace
Posts: 213
Joined: Wed 14 Feb 2007 08:26

using encryption and compression

Post by brace » Thu 25 Mar 2010 10:48

Is it possible to compress data when sent across the network together with encryption?

THe idea is to minimize network traffic.

Dimon
Devart Team
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Joined: Mon 05 Mar 2007 16:32

Post by Dimon » Thu 25 Mar 2010 13:49

SQL Server doesn't support compressing of transferred data.
SDAC allows to compress blobs only. For more detailed information see the TCompressedBlob class description in the SDAC help.

brace
Posts: 213
Joined: Wed 14 Feb 2007 08:26

Post by brace » Fri 02 Apr 2010 11:05

There are no info on CompressBlobMode for TMSQuery

ms-help://embarcadero.rs2009/Devart.Sdac/Sdac/Devart.Sdac.TCustomMSDataSet.Options.htm

Anyway i tired to run a query on a table that contains one blob field and if CompressBlobMode is cbClient or CBClientServer the query opens 3 times slower, while I was expecting the opposite.

Why?

Dimon
Devart Team
Posts: 2888
Joined: Mon 05 Mar 2007 16:32

Post by Dimon » Tue 06 Apr 2010 06:49

Data compressing is effective in case of slow network, where capacity of transferred data has critical meaning. In network with high speed of data transferring (for example in local network), application works more slowly when data compressing is used, because time is spent on data compressing/decompressing.

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