# Performance questions ...
**URL:** https://discourse.orthanc-server.org/t/performance-questions/61
**Category:** Google Groups archive
**Created:** [May 2, 2014, 2:46pm UTC](https://discourse.orthanc-server.org/t/performance-questions/61 "2014-05-02T14:46:49Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Raul\_Alexis\_Betancor](https://discourse.orthanc-server.org/u/Raul_Alexis_Betancor)
#### Post date: [May 2, 2014, 2:46pm UTC](https://discourse.orthanc-server.org/t/performance-questions/61/1 "2014-05-02T14:46:49Z")
During my test of Orthanc as a PACS replacement for our old and now dead ClearCanvasServer, I noticed a slowdown on querys that I don’t undestand why … so increased the log level with --trace, and got this:
I0502 16:38:39.940242 5974 CommandDispatcher.cpp:266] Association Received
I0502 16:38:39.940793 5974 CommandDispatcher.cpp:445] Association Acknowledged (Max Send PDV: 16372)
I0502 16:38:39.979681 5997 OrthancFindRequestHandler.cpp:485] DICOM C-Find request at level: Study
I0502 16:38:39.979709 5997 OrthancFindRequestHandler.cpp:491] (0008,0052) QueryRetrieveLevel = STUDY
I0502 16:38:39.979722 5997 OrthancFindRequestHandler.cpp:491] (0010,0020) PatientID = _mico_
I0502 16:38:39.979734 5997 OrthancFindRequestHandler.cpp:491] (5555,0010) PrivateCreator = AETMED RETRIEVE INFO
I0502 16:38:39.979841 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:39.979925 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:39.979950 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:39.979974 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:39.979991 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:39.980015 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:39.980032 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
[…]
I0502 16:38:40.169436 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:40.169448 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:40.169458 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:40.169467 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:40.169477 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE resourceType=?
I0502 16:38:40.182185 5997 OrthancFindRequestHandler.cpp:543] Number of candidate resources after exact filtering: 13109
I’m new to Orthanc … and I must admit that still have not take a look at the code … but why is that query repeated for EACH resource that it’s stored on the BD?
After that queries … apears some more … repeated more, and more …
I0502 16:38:40.182261 5997 Statement.cpp:116] SQLite::Statement::Step SELECT internalId, resourceType FROM Resources WHERE publicId=?
I0502 16:38:40.182302 5997 Statement.cpp:116] SQLite::Statement::Step SELECT internalId, resourceType FROM Resources WHERE publicId=?
I0502 16:38:40.182342 5997 Statement.cpp:116] SQLite::Statement::Step SELECT resourceType FROM Resources WHERE internalId=?
I0502 16:38:40.182399 5997 Statement.cpp:116] SQLite::Statement::Step SELECT a.internalId FROM Resources AS a, Resources AS b WHERE a.parentId = b.internal
Id AND b.internalId = ?
I0502 16:38:40.182421 5997 Statement.cpp:116] SQLite::Statement::Step SELECT a.internalId FROM Resources AS a, Resources AS b WHERE a.parentId = b.internal
Id AND b.internalId = ?
I0502 16:38:40.182446 5997 Statement.cpp:116] SQLite::Statement::Step SELECT a.internalId FROM Resources AS a, Resources AS b WHERE a.parentId = b.internal
Id AND b.internalId = ?
I0502 16:38:40.182451 5997 Statement.cpp:116] SQLite::Statement::Step SELECT a.internalId FROM Resources AS a, Resources AS b WHERE a.parentId = b.internal
Id AND b.internalId = ?
I0502 16:38:40.182462 5997 Statement.cpp:116] SQLite::Statement::Step SELECT resourceType FROM Resources WHERE internalId=?
I0502 16:38:40.182477 5997 Statement.cpp:116] SQLite::Statement::Step SELECT a.internalId FROM Resources AS a, Resources AS b WHERE a.parentId = b.internal
Id AND b.internalId = ?
I0502 16:38:40.182489 5997 Statement.cpp:116] SQLite::Statement::Step SELECT a.internalId FROM Resources AS a, Resources AS b WHERE a.parentId = b.internal
Id AND b.internalId = ?
I0502 16:38:40.182499 5997 Statement.cpp:116] SQLite::Statement::Step SELECT resourceType FROM Resources WHERE internalId=?
I0502 16:38:40.182533 5997 Statement.cpp:116] SQLite::Statement::Step SELECT publicId FROM Resources WHERE internalId=?
I0502 16:38:40.182553 5997 Statement.cpp:116] SQLite::Statement::Step SELECT resourceType FROM Resources WHERE internalId=?
I0502 16:38:40.182566 5997 Statement.cpp:116] SQLite::Statement::Step SELECT a.internalId FROM Resources AS a, Resources AS b WHERE a.parentId = b.internal
Id AND b.internalId = ?
[…]
Where could I star to debug and trace that queries ? … why params of the query are not show on the log?
Best regards
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### Author:  [@jodogne](https://discourse.orthanc-server.org/u/jodogne)
#### Post date: [May 3, 2014, 9:26am UTC](https://discourse.orthanc-server.org/t/performance-questions/61/2 "2014-05-03T09:26:10Z")
Hello,
It is really hard for me to give you any hint, without having access to your SQLite database.
What is your DICOM client? How many patients/studies/series/instances are stored on your system (this information can be found by querying [http://localhost:8042/statistics](http://localhost:8042/statistics))? Your experienced slowdown might be tightly linked to the behavior your DICOM client.
In my own opinion, this is quite normal to have a lot similar SQLite requests. The first query is issued by your DICOM client to retrieve the list of studies of the patient whose ID is “_mico_”. Then, for each of these studies, your DICOM client issues a request to get the series of this study.
When you type an exact Patient ID, without wildcards (such as “Amicon”), you should notice an huge improvement in speed.
Sébastien-