better documentation of data in BigQuery

[milanwiedemann]

it would be useful to have information for some of the tables that we're using in this project

general descriptions:

• where the underlying data is coming from (e.g., import of .csv file from https://isd.digital.nhs.uk/trud)
• how often is the underlying data updated (weekly, monthly) and how often do we update the tables
• are any data manipulations done prior (or after) to uploading the data to bigquery (e.g., replacing empty strings with null)
• what are the known issues with the data?
• what are the advantages of this table compared to other similar available datasets?

field name descriptions

• further details describing each field name (e.g., DDD_UOMCD = Daily Defined Dose Unit of Measure Code)

we could for example use the description filed to add this information:

[milanwiedemann]

tag for reference, let me know if you have any further thoughts @rose-higgins @HelenCEBM @robinyjpark @Jongmassey @brianmackenna do we need to add someone from tech team?