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RECBYT indexes were introduced in the FairCom DB ISAM API to provide improved space management for variable-length records in a table and to permit backward physical traversal of data files that contain resources and variable length records. A RECBYT index is based on the byte offset (recbyt) of the record being indexed.
RECBYT indexes are optional and the user can disable their creation by specifying the CTCREATE_NORECBYT when the table is created.
When a table is created with RECBYT index support, a RECBYT index is automatically created for the table. The operations on the RECBYT indexes are transparent to the user except for an added performance overhead. FairCom DB API will automatically update the index entries. The RECBYT index will not appear in the list of indexes for a table. The user cannot alter or delete the components of the RECBYT index. The use of RECBYT index has no impact on the fields in the record buffer of a table. There is no field associated with this index.
Note: The RECBYT index enables backward physical traversal of variable-length records. By default, the FairCom DB API API creates this index on every table. Because it is an extra index, it slows inserts, updates, and deletes. Unless you need to walk variable-length records backwards, disable the creation of the index by adding NORECBYT to the table create mode.
