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Shadow tables are often used as layers between the end-user and the database. For example, if a user logs into his/her bank account and requests a history of all his/her past transactions, the database usually stores all transactions for all users in one huge table and distinguishes the parties involved in each transaction in one specific ...
Query plan. A query plan (or query execution plan) is a sequence of steps used to access data in a SQL relational database management system. This is a specific case of the relational model concept of access plans. Since SQL is declarative, there are typically many alternative ways to execute a given query, with widely varying performance.
Nested SQL. In relational databases, a nested table is a table that is embedded within another table. Individual elements can be inserted, updated, and deleted in a nested table. Since individual elements can be modified in a nested table, they are more flexible than an array because elements in an array can only be modified as a whole, not ...
Statistical database. A statistical database is a database used for statistical analysis purposes. It is an OLAP (online analytical processing), instead of OLTP (online transaction processing) system. Modern decision, and classical statistical databases are often closer to the relational model than the multidimensional model commonly used in ...
In addition, the child and parent table may, in fact, be the same table, i.e. the foreign key refers back to the same table. Such a foreign key is known in SQL:2003 as a self-referencing or recursive foreign key. In database management systems, this is often accomplished by linking a first and second reference to the same table.
View (SQL) In a database, a view is the result set of a stored query, which can be queried in the same manner as a persistent database collection object. [1] This pre-established query command is kept in the data dictionary. Unlike ordinary base tables in a relational database, a view does not form part of the physical schema: as a result set ...
Database encryption can generally be defined as a process that uses an algorithm to transform data stored in a database into "cipher text" that is incomprehensible without first being decrypted. [1] It can therefore be said that the purpose of database encryption is to protect the data stored in a database from being accessed by individuals ...
Data Access Language for the Macintosh, or simply DAL, was a SQL -like language and application programming interface released by Apple Computer in 1990 to provide unified client/server access to database management systems. It was known for poor performance and high costs, something Apple did little to address over its short lifetime, before ...