dcmqscr max limits

[Ahmed_Zikry]

Hello,

Regarding dcmqrscp.exe Quota Format: ( maxStudies, maxBytesPerStudy )
what is the max limits for maxStudies and maxBytesPerStudy that i can set?

[Michael Onken]

Hi,

after looking into the (configuration parsing) code of dcmqrdb, my impression is that:

• for maximum number of studies, you can safely assume the size of a (signed) int, which according to the C standard must at least hold 16 bit, i.e. allows a positive maximum of 32767.
• for maximum number of studies, you can safely asssume the size of a (signed) long, which according to the C standard must at least hold 32 bit, i.e. allows a positive maximum of 2147483647. Note that this is the resulting number of bytes (while you can specify the value in GB, MB or KB, too).

Probably on many current machines int and long are bigger. However, I would not bet that the overall code of dcmqrdb does not restrict those values implicitly somewhere...

Note that dcmqrdb uses an index file to keep track of studies, series and images. It will perform badly if you feed tons of data inside since it is searched in a linear fashion. On the other hand we heard of users who actually use lots of data (and removed some hard boundaries in the code), who are still satisfied. I would not recommend this.

The whole module has never meant to serve as a real PACS but originally has been developed for demonstrating the DICOM Q/R and storage services in 1993. There have always been plans (and code fragments) to alternatively use an SQL (or similar) backend instead but so far this has never had high priority.

HTH,
Michael

[J. Riesmeier]

Actually, there are some hard-coded limits in the source code:

Code: Select all

#define MAX_MAX_STUDIES         DB_UpperMaxStudies
#define MAX_NUMBER_OF_IMAGES    10000

And:

Code: Select all

/// upper limit for the number of studies per storage area
#define DB_UpperMaxStudies              500

/// upper limit for the number bytes per study
#define DB_UpperMaxBytesPerStudy        0x40000000L

There is also a maximum size for the "index.dat" file, which is 32 MB if I remember correctly.

[Michael Onken]

Ah, thanks for the additional information, Jörg, I have not been aware of these

[Ahmed_Zikry]

Thanks for your support about my question.
I have another questions:
1- What will happen if the number of the studies exceeded Max size (will it drop the oldest or ignore the new study)
2- What will happen if the max size of the index.dat is reached
3- Is it possible in case of reaching Max size of (studies/index.dat) to move to another saving directory and at the same time.