For the invisible indexes in oracle 11g pdf program, see Europress. For a topical guide to this subject, see Outline of databases. An example of output from an SQL database query.
A database is an organized collection of data. A relational database, more restrictively, is a collection of schemas, tables, queries, reports, views, and other elements. A general-purpose DBMS allows the definition, creation, querying, update, and administration of databases.
A database is not generally portable across different DBMSs, but different DBMSs can interoperate by using standards such as SQL and ODBC or JDBC to allow a single application to work with more than one DBMS. 1980s have all supported the relational model – generally associated with the SQL language. Sometimes a DBMS is loosely referred to as a “database”. Formally, a “database” refers to a set of related data and the way it is organized.