Search results
Results from the WOW.Com Content Network
A schema migration is performed on a database whenever it is necessary to update or revert that database's schema to some newer or older version. Migrations are performed programmatically by using a schema migration tool. When invoked with a specified desired schema version, the tool automates the successive application or reversal of an ...
The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS). The term " schema " refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases ).
In computing and data management, data mapping is the process of creating data element mappings between two distinct data models.Data mapping is used as a first step for a wide variety of data integration tasks, including: [1]
A schema crosswalk is a table that shows equivalent elements (or "fields") in more than one database schema. It maps the elements in one schema to the equivalent ...
Data migration is the process of selecting, preparing, extracting, and transforming data and permanently transferring it from one computer storage system to another. . Additionally, the validation of migrated data for completeness and the decommissioning of legacy data storage are considered part of the entire data migrati
Complex: When the database has many external dependencies, making changes to the schema becomes all the more complicated as the external dependencies should also be updated to cope up with the changes made in the database schema. With the increase in number of dependencies, Evolutionary Database Design approach becomes extremely complex.
A database over a schema is defined as a set of sets, one for each relation (in a relational database). The database corresponding to the source schema would comprise the set of sets of tuples for each of the heterogeneous data sources and is called the source database. Note that this single source database may actually represent a collection ...
The terms schema matching and mapping are often used interchangeably for a database process. For this article, we differentiate the two as follows: schema matching is the process of identifying that two objects are semantically related (scope of this article) while mapping refers to the transformations between the objects.