Reader's Clinic - Incorrect Indexes

A Cardiff user recently experienced a peculiar problem with selects. Every time all records for the 27th October 1989 were selected, all records for the 26th were returned instead. This worked perfectly before the date in question but all requests after this date were incorrect. The same problem also befell a user in London.

Whilst it was not immediately apparent, the problem was caused by record ids containing value marks. The developer had accidentally used a multiple choice popup on the key prompt and the user had selected two ids. This had contructed a new record with an id containing a value mark, which had been filled in and filed.

Unfortunately when the record id contaning the value mark was inserted into the index node, the system thought that a node delimiter was being inserted into the indexing record and thus all successive index records were put one place out of alignment.

The solution was to write a program that scanned for records with value marks in the id then deleted them. When this was completed the index was rebuilt and the problem disappeared.

(Volume 1, Issue 10, Page 3)