RDBMS - Auxiliary Data Structure

1 - Auxiliary

Auxiliary data structures that constitute logical replications of data from one or more columns of a table. E.g.:

  • indexes,
  • materialized views,
  • summary tables,
  • structures used to enforce relational integrity constraints,

Auxiliary data structures contain copies of, references to, or data computed from base table data, deleting data from an auxiliary data structure does not result in the loss of base table data in that it is still contained in the base table data structure. In contrast, deleting data from a base table data structure does result in the loss of base table data.

3 - Type

There are two types of auxiliary data structures:

  • Implicit (ADS)
  • and explicit. (EADS)

3.1 - Explicit

An explicit auxiliary data structure (EADS) is created as a consequence of a directive (e.g. DDL, session options, global configuration parameters).

These directives are called EADS Directives.

3.2 - Implicit

Any ADS which is not an EADS is by definition an Implict ADS (IADS).

4 - Documentation / Reference

data/type/relation/data_structure.txt · Last modified: 2018/07/06 12:30 by gerardnico