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If you instruct Db2 to validate XML data against an XML schema prior to storage, Db2 annotates all nodes in the XML hierarchy with information about the schema types; otherwise, it will annotate the nodes with default type information. Upon storage, Db2 preserves the internal structure of XML data, converting its tag names and other information ...
In relational databases, the information schema (information_schema) is an ANSI-standard set of read-only views that provide information about all of the tables, views, columns, and procedures in a database. [1]
A trigger in Sedna is set on any nodes of an XML document stored in database. When these nodes are updated, the trigger automatically executes XQuery queries and updates specified in its body. For example, the following trigger cancels person node deletion if there are any open auctions referenced by this person:
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 ).
Materialized views were introduced by Oracle Database, while IBM Db2 provides so-called "materialized query tables" (MQTs) for the same purpose. Microsoft SQL Server introduced in its 2000 version indexed views which only store a separate index from the table, but not the entire data. PostgreSQL implemented materialized views in its 9.3 release.
A true fully (database, schema, and table) qualified query is exemplified as such: SELECT * FROM database. schema. table. Both a schema and a database can be used to isolate one table, "foo", from another like-named table "foo". The following is pseudo code: SELECT * FROM database1. foo vs. SELECT * FROM database2. foo (no explicit schema ...
SQL Server SEQUENCE (starting from SQL Server 2012) [7] PostgreSQL or IBM Informix serial; MySQL AUTO_INCREMENT; SQLite INTEGER PRIMARY KEY (if AUTOINCREMENT is used it will prevent the reuse of numbers that have already been used but are available) [8] AutoNumber data type in Microsoft Access; AS IDENTITY GENERATED BY DEFAULT in IBM Db2 and ...
Datasource – name given to the connection set up to a database from a server. The name is commonly used when creating a query to the database. The Database Source Name (DSN) does not have to be the same as the filename for the database. For example, a database file named "friends.mdb" could be set up with a DSN of "school".