Data Dictionary
Overview
Data dictionary, metadata repository (synonym), is a compilation of data model constituents which come in handy to the people who want to dig into them. A data dictionary has constituents such as a catalog of all database dossiers, the count of records per every dossier, the identity and category per every field. However, from the outlook of a management structure of a database, the meaning of a data dictionary changes to, a set of tables which are limited to being read only and cannot be distorted.
Uses of data dictionary
Basically, the data dictionary has got three uses namely: using the data dictionary to dig into the personal information regarding of the one using it, the arrangement of the storage and the plan of the object. All this is dug into by the Oracle; it is handy since it (the data dictionary) can be used by whichever oracle as a allusion limited to read only by the user for referring to the information contained in the database; and whenever a DDL (Data Definition Language) is given, the data dictionary comes into usage since it’s used by the Oracle for upgrading.
The data dictionary also serves other varying purposes such as: dividing the database into two segments namely: regional and logical; ascertaining that there is admission to proficient data mostly concerning the use of catalogs; propping up the design of an automatic database that has active strictures for the storage allotment; indicate justification criterion and restriction to references which are imposed in a king of automation; and the provision of already delineated types of records designed for the features of Rich Client , for example distributed processing and Attached Objects (Charles, 1993). An example is that of a number of banks design the data items that are applied in the client banking.
Importance of data dictionary
In whichever course of the development of the software, a data dictionary has a vital function because: It gives a terminology which is uniform for all the pertinent data that’s to be used by the users (mostly the engineers) in a specific venture who use wide ranging terms to mean the same data and it can be a basis for misunderstandings; there data dictionary is important in that it gives the analysts the provisions of ways to find out the meaning of the varying data formations as in the factors that constituent it.
The implementation of data dictionary
The data dictionary is made in such a way that it is elastic in its implementation and therefore there are no suppositions as in the complicity of the digital collection structure under which the implementation of the data dictionary would follow (Rom, 1968).The type ‘technical neutrality’ designed on the data dictionary is directed to get the most out of the dictionary’s applicability on the extensive assortment of digital safeguarding framework through which it could probably be implemented.
The importance of implementing data dictionary is: the mutual registries, the vendor prop up, the tools that can be reused over again, the depository authorization and the inter-depository information swap over. Nevertheless, the PREMIS Editorial Committee with a set of rules and regulations regarding the PREMIS data dictionary implementation (conformance statement). The rules work at via stages namely: Semantic and Data dictionary units. In the Semantic unit, the conformant information execution is characterized by the specific semantic data dictionary element while in the data dictionary, the execution of the conformant.
Moreover, the two principles are also applicable to two additional situations namely: the peripheral conformance and interior conformance. The peripheral conformance uses the outlook of cross-depository connection under which the there is the swap over of the PREMIS information while the interior conformance uses the outlook of the interior application of one depository.
An example of rules of application is: (conformant) a depository opts to record regarding Objects and in such cases, the depository then executes the components of metadata which on the lowest range, cover up all data identified in the semantic elements which are obligatory as in for the Objects type of dossier.
The advantages and disadvantages of data dictionary
Advantages
There are many advantages of data dictionary among them:
Clarity: the data dictionary enables the developer to have the access to clear and fit for use data and therefore it props up the competent and reliable utilization of data by the designers and the different users without the considerations of the partition group they fit in.
Consistency: commercial data, depositories cannot be triumphant unless they are always dug onto since the data is utilization transcends the borders of the organization.
Completeness: more so to an analyst, the data dictionary assists on situations whereby the data is unclear or incomplete by pointing out to what is implied by entirety and the regulations for constructing an absolute formation of data.
Reusability: the data dictionary prop up reliability of which is a vital component regarding the aptitude of one partition of organization to integrate pre-planned, pre-tested and verified work by the company for using again in their personal latest growth initiatives (David, 2003). This second inventing spares capital and time.
The disadvantage of data dictionary is they are not strong when it comes to put on view both the input and output element.
Conclusion
For the success of an EHR system, there comes a vital need for the creation and the maintenance of a data dictionary. There is also much importance into the arrangement and maintenance of that vital information. Using the AWR for user recognized statistics, the basic history information can be accessed whereby the users are lead through the course by AWR abilities in the performance of more advanced tuning and trend analysis.
References

Charles, W. (1993). Data Dictionary: Concepts and Uses. New Jersey : John Wiley & Sons Australia Ltd.
David, K. (2003). Oracle data dictionary pocket reference. Sebastopol: O’Reilley Media Inc.
Rom, N. (1968). Data dictionary: implementation, use, and maintenance. Richmond: Prentice Hall.