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I was thinking of turning this on some large databases not just mail files. We have around 8-10GBs of large databases and a 200MB of small databases.

But after reading this post I am not too sure.

Can anyone confirm whether this is true? Are there any ill effects on performance by turning this feature on and if so what's the difference in performance?

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The points in that post are valid. You will see some space reduction from turning on design/data compression, but how much you will see depends on the composition of your databases. Databases with more design elements will see more benefit from design compression. Since data compression only works on rich text data, not plain text or attachments, the improvement you will see depends on whether your databases have lots of rich text. (If you have lots of attachments, you should also be using DAOS and LZ1 compression.)

It is also true that you will incur some performance overhead doing compression and decompression, but it's something of a tradeoff- more CPU usage for less I/O traffic. Since many Domino servers are more I/O-bound than CPU-bound, this could indeed be a worthwhile tradeoff for you.

The only way to know how much space you will save or performance impact you will see in your environment is to test it, carefully measuring the results against your current performance baseline. Hopefully you are already capturing Domino statistics related to CPU, memory, disk and network usage- if not, do so for a few months to get a feeling for how your server performs and then turn on one compression feature at a time to see what impact you get.

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  • Thank you Rob, this change requires a compact and we are using transaction logging, so compact is not something we do regularly and we are not using a lot of rich text fields in our application. Do you know if the compression/decompression happen for rich text data only or for the whole document regardless of whether it has rich text data or not?
    – pipalia
    Apr 4, 2012 at 16:41
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    It only compresses "non-summary" data, which would be rich text. Reference: publib.boulder.ibm.com/infocenter/domhelp/v8r0/topic/…
    – Rob Darwin
    Apr 4, 2012 at 17:43
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Some question:

1.) Why didn´t you enable DAOS? This is a nice space saver, but it depends on the settings and the stuff which is in the users mailfiles.

2.) Why didn´t you run compact on a regular basis? If a domino .nsf isn´t compacted (lo compact -c xyz.nsf) then the whitespace isn´t released. This also affects the performance. A mailfile which is 10 GB in size on the disk, but require only 500 MB (after compacted) hasn´t a very great performance.

Some maybe useful links: * Upgrading existing attachments from Huffman to LZ1 compression * Space saving via compact

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