Search results
Results from the WOW.Com Content Network
In standard SQL:1999 hierarchical queries are implemented by way of recursive common table expressions (CTEs). Unlike Oracle's earlier connect-by clause, recursive CTEs were designed with fixpoint semantics from the beginning. [1] Recursive CTEs from the standard were relatively close to the existing implementation in IBM DB2 version 2. [1]
The SQL:1999 standard calls for a Boolean type, [1] but many commercial SQL servers (Oracle Database, IBM Db2) do not support it as a column type, variable type or allow it in the results set. Microsoft SQL Server is one of the few database systems that properly supports BOOLEAN values using its "BIT" data type [citation needed]. Every 1–8 ...
PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM Db2 (since version 9.7). [ 11 ] O-PL/SQL allows the definition of classes and instantiating these as objects, thus creating user-defined datatypes as writing constructors, beyond using Java in stored procedures and triggers.
Cursors are usually closed automatically at the end of a transaction, i.e. when a COMMIT or ROLLBACK (or an implicit termination of the transaction) occurs. That behavior can be changed if the cursor is declared using the WITH HOLD clause (the default is WITHOUT HOLD). A holdable cursor is kept open over COMMIT and closed upon ROLLBACK.
The recursive join is an operation used in relational databases, also sometimes called a "fixed-point join". It is a compound operation that involves repeating the join operation, typically accumulating more records each time, until a repetition makes no change to the results (as compared to the results of the previous iteration).
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
The study by Cornell University's Jeb E. Brooks School of Public Policy’s Program on Applied Demographics projects that New York faces a significant population decline due to low fertility rates ...
Multidimensional Expressions (MDX) is a query language for online analytical processing (OLAP) using a database management system. Much like SQL, it is a query language for OLAP cubes. [1] It is also a calculation language, with syntax similar to spreadsheet formulae.