Dataset details: CRDA/37/DS/2

The Access database preserved here is derived from five databases created to simplify management of the British Rail Privatisation Archive. Each Document record should contain a brief description of the material to which the record relates, the department or subsidiary company that generated the material, correspondence reference, originator and time frame.

The dataset derived from the Access database is an updated version of that transferred to NDAD in 2000 (see Links to related datasets). It contains additional records added to the Documents table, though the other content remains the same. NDAD did not receive additional copies of the documents transferred in 2000; but this updated version of the database acts as a finding aid for the documents in the privatisation archive. No further transfers of the database are expected, and this dataset reflects the final version of the database.

The database was designed to facilitate searches for documents based on several key attributes, most notably by originating British Railways Board department; by subsidiary company; and by document category. For background information on the British Railways Board privatisation archive and the BREAD system see the Series Catalogue.

The Access database converted and preserved here is 'breadtab.mdb'. This is an updated version of the main database file supplied for the preceding dataset in this Series (CRDA/37/DS/1).

The object definitions of 'breadtab.mdb' have been exported using the Database Documenter tool supplied by Microsoft with Access 97, and are included among the Dataset Documentation (see the Dataset Documentation Catalogue, reference CRDA/37/DD/4/2/3).

The tables in 'breadtab.mdb' were exported from the database file in comma-separated format (CSV), using the standard conversion tools supplied by Microsoft with Access 97. A standard procedure was followed for removing DOS line-endings and for converting to the ISO 8859(1) character set.

The three additional tables in dataset CRDA/37/DS/1 (Images, MultiSection, SeparateSection) created from data on the 64 CDs containing the scanned document images from the Oracle/Optika system, have been preserved with that dataset, but the Documents table in this dataset can be joined with those tables using the same keys as for the Documents table in CRDA/37/DS/1.

The forms and reports associated with this data are those in the file "bread.mdb" accessioned as part of CRDA/37/DS/1. Example screenshots and MS Access documenter output can be found in the Dataset Documentation Catalogue.

The tables in this dataset should be used in conjunction with the tables Images, MultiSection and SeparateSection that are included in the earlier dataset (see also Digital processing and conversion ).

The dataset comprises the following table(s):

Although the Access database was clearly of great value to its users as a way of locating documents, the data suffers from a lack of on-entry validation of field values, and enforcement of referential integrity among its logical relationships. Inconsistencies in case ("Blink", "BLINK"), punctuation ("VEN", "VEN.") and trailing spaces ("Mins", "Mins ") vitiate many links between tables. The following points were noted in analysing this dataset, for comparison with the previous dataset in this series):

Unmatched codes

Many records in the Documents table contain either null values or unmatched codes in fields which should join to a corresponding lookup table. Some of the missing codes have been established and are recorded in the Field Descriptions.

Row numbers and Record IDs

The UniqueID field in the Documents table is a row number which was automatically generated by Access as each new record was created. However, the highest value in UniqueID (93375) does not match the number of records in the Documents table (93134), because of breaks in the sequence (including the gap between UniqueID 90331 through 90341 (inclusive) identified in the earlier dataset).

As identified in the earlier dataset, for three records in the Documents table where ParentID has been specified, miskeying by the person entering the data has resulted in clearly erroneous references to non-existent Document records. For these records, NDAD has identified with reasonable certainty what the real ParentID should be:

Missing Values

The following is a summary for each field in the Documents table of the number of rows with blank, null or spaces entered in that field (zeros are not, for the purpose of this analysis, interpreted as missing values):

Additionally the record with UniqueID 92580 has a date in the DocumentGroupID field.

Derived tables

Of the records in the Documents table, 20076 have related entries in the Images table; 14693 have related records in the MultiSection table. The Image records with UniqueID 90331 through 90341 inclusive (11 in all) have no corresponding record in the Documents table. These records also occur in the MultiSection table.

Post-processing checks were carried out on the converted data file to ensure the number of records and fields was identical with the original database application, and anomalous field contents were verified against the original database.