| Version 6 (modified by , 13 years ago) ( diff ) |
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i2b2 Ontology and CRC Discussion: 1
Questions asked and points to ponder. Access to the demo database is useful here...
Ontology Cell tables compared to CRC concept_dimension table
There are three ontology tables within the demo Ontology cell: birn, i2b2 and custom_meta.
When I do a select count(*) from <table_name> where c_visualattributes like '%LA%' I get the following figures:
- birn: 37
- custom_meta: 0
- i2b2: 93807
When I do a "select count(*) from concept_dimension" within the CRC cell I get a count of 73590.
The totals are 93844 as opposed to 73590. Why is there a difference and what does it mean?
In an Ontology table, what does c_columndatatype really mean?
The docs state: "either ‘T’ for text or ‘N’ for numeric and describes the datatype of the concept". Yet the length of the column is varchar 50.
Within the demo project:
- select count(*) from i2b2 where c_columndatatype like '%N%' ===> returns 0
- select count(*) from i2b2 where c_columndatatype like '%T%' ===> returns 134762
- select count(*) from i2b2 ===> returns 134762
Yet within the query tool (from the Workbench) I can select terms from a Labtest and constrain by value. This is undoubtedly possible because of the optional metadataxml column. But even so, what does c_columndatatype really mean?
The following point may be of some relevance...
