The JSOC data record
A data record is the basic "atomic unit" of a dataseries, or more precisely: The smallest unit that will be individually registered and available for export from a data series in the JSOC catalog. Most (if not all) access to the JSOC archive by both pipeline processing modules and external data export services will be in terms of data records. In other words, what we informally call the "JSOC catalog" is first and foremost a data record catalog.
Datarecords are each associated with a record number within their parent dataseries. The record number is an ordinal index number assigned internally by the DRMS to each new record being created. It increments by one for every new record, and so maps to record creation order. The series name and record number together uniquely identifies a data record within the DRMS catalog.
All data records belonging to the same data series have identical logical structure, meaning that they have the same keywords, links, and data segments. These terms will be defined in more detail below. Keywords, links, and segment descriptions will also be referred to as meta-data.
None, one, or more (up to five) keywords can be declared PrimaryIndex keywords for each dataseries. These special keywords will have indexes in the database enabling more rapid searches and they can be used to simplify the record query used in accessing Record Sets.
The DRMS Application Programming Interface (API) provides a set of functions, with bindings to host languages including C, FORTRAN, IDL, and maybe MATLAB, that allow programs to connect to the DRMS environment and retrieve and manipulate data records. The API contains groups of functions that
- create, read or update data records,
- query the JSOC catalog database to retrieve data records whose keywords satisfy a given condition,
- get and set the contents of keywords, links and data segments,
- create new or modify existing data series.