DD: data dictionary, used by CRATE to build a de-identified
research database from source data.
FK: foreign key, a cross-reference to a PK in another table.
MRID: master patient research identifier.
NLP: natural language processing, in which computers read free
text to extract structured data.
NOT NULL: a column that is not allowed to contain NULL values.
NULL: a missing or blank value.
PK: primary key, the main column (or sometimes columns)
defining and indexing rows of a table.
SQL: Structured Query Language, the standard language for
defining and querying databases.
RID: patient research identifier.
TRID: transient patient research identifier; this can be useful
for fast cross-referencing within SQL queries, but will change
when the database is rebuilt.
URL: uniform resource locator.
UTC: coordinated universal time (also known as Greenwich Mean
Time, Western European Time).
Notes:
This CRATE report for researchers was generated by scanning a
research database and summarizing key features (including by
reference to a CRATE data dictionary). CRATE version:
{{ CRATE_VERSION }}.
The number of distinct non-null values is taken from SELECT
COUNT(DISTINCT some_column), which does not include NULL
values. The actual distinct values, if shown, are taken from
SELECT DISTINCT some_column, which does include NULL values.