The AQDB uses a relational model that is implemented joining "classification" tables to the data using numerical id's rather than always storing the complete names in each cell in a table. Numerical id's make search and retrieval operations faster as numeric indices are more efficient than text indices. Numeric indices are, however, more difficult to interpret and therefore a header file relating the numeric indices to their text counterparts has been included in the output file.

There are three options available for previewing the data:

Concise:

The Concise format produces an output file which uses the field codes rather than the full text names. This makes search and retrieval faster but is less informative to view. Reading the header file will help clarify the codes in the data.

Verbose:

The Verbose format contains the actual field names which is more informative but generally slower to retrieve.

as Text Only:

The as Text Only option allows the user to preview the selected data as a comma-delimited text file.