# why not use database table like patient/study/series/image to save the element ?
**URL:** https://discourse.orthanc-server.org/t/why-not-use-database-table-like-patient-study-series-image-to-save-the-element/2329
**Category:** Google Groups archive
**Created:** [February 18, 2021, 6:48am UTC](https://discourse.orthanc-server.org/t/why-not-use-database-table-like-patient-study-series-image-to-save-the-element/2329 "2021-02-18T06:48:54Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Jiwen\_Chen](https://discourse.orthanc-server.org/u/Jiwen_Chen)
#### Post date: [February 18, 2021, 6:48am UTC](https://discourse.orthanc-server.org/t/why-not-use-database-table-like-patient-study-series-image-to-save-the-element/2329/1 "2021-02-18T06:48:54Z")
the database table like maindicomtag is not good at the performance. So why not use the table to split the element to different level, just like value of column resourcetype in table resources ?
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### Author:  [@jodogne](https://discourse.orthanc-server.org/u/jodogne)
#### Post date: [February 18, 2021, 7:20am UTC](https://discourse.orthanc-server.org/t/why-not-use-database-table-like-patient-study-series-image-to-save-the-element/2329/2 "2021-02-18T07:20:01Z")
Feel free to develop and publicly share a new database index plugin if you want to propose another database schema:
[https://book.orthanc-server.com/plugins.html](https://book.orthanc-server.com/plugins.html)
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### Author:  [@Jiwen\_Chen](https://discourse.orthanc-server.org/u/Jiwen_Chen)
#### Post date: [February 18, 2021, 7:29am UTC](https://discourse.orthanc-server.org/t/why-not-use-database-table-like-patient-study-series-image-to-save-the-element/2329/3 "2021-02-18T07:29:08Z")
yeah, i see. But I just wanna know why choose the table format like maindicomtag. Is there any important stuff to consider ?
在2021年2月18日星期四 UTC+8 下午3:20:01[s.jo...@gmail.com](mailto:s.jo...@gmail.com) 写道：
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### Author:  [@jodogne](https://discourse.orthanc-server.org/u/jodogne)
#### Post date: [February 18, 2021, 7:35am UTC](https://discourse.orthanc-server.org/t/why-not-use-database-table-like-patient-study-series-image-to-save-the-element/2329/4 "2021-02-18T07:35:38Z")
This format was chosen to be as close as possible to the “patient/study/series/instance” DICOM model of the real-world:
[https://book.orthanc-server.com/dicom-guide.html#model-of-the-real-world](https://book.orthanc-server.com/dicom-guide.html#model-of-the-real-world)
Furthermore, besides being associated with instances, the so-called “main DICOM tags” are also associated with patients, studies and series.