Database Reference
In-Depth Information
was included. PL/SQL allows execution of SQL commands in blocks,
where sequentially executed lines of code can depend on previously
executed lines of code, much like a programming language. SQL is not
a programming language, however. SQL is a coded tool or shorthand
method of accessing groups of rows from a relational database.
Early 1990s
. Oracle7 was released. Oracle7 included Referential
Integrity, cost-based statistics for optimization, and clustering. Ref-
erential Integrity is important for automated maintenance of accu-
racy of related data sets. Cost-based optimization uses statistics,
providing a realistic picture rather than one based on “intelligent”
rules. Rule-based optimization is a best guess for query performance
optimization. Cost-based optimization is vastly superior to rule-
based optimization. Finally, clustering allows for fail-over, scalability,
and high availability.
Mid-1990s
. The release of Oracle8 introduced the concept of the
Object-Relational database for Oracle Corporation. Additionally,
thin client and application server capabilities were introduced.
Late 1990s
. The first Internet database Oracle Database 8
i
was
released. Oracle Database 8
was specifically designed for database
Internet access and performance. In addition, database kernel-exe-
cuted Java procedures were introduced. Java or Java Virtual Machine
(JVM) executed code is much more capable of complex coding than
PL/SQL. However, there is something to be said for maintaining
simplicity and sticking to only relational methodologies in a rela-
tional database. Mixing of relational and object methods can some-
times create more complexity than it solves. Object databases are
excellent tools for resolving complexity. Relational databases can
become drastically or even disastrously difficult to understand and
maintain when attempting to cater for complexity.
i
Y2K
. The second-generation Internet database Oracle Database 9
i
was released. Oracle Database 9
i
has improvements over that of Ora-
cle Database 8
. Middle-tier application server and Oracle tools inte-
gration were also introduced.
i
2003.
is the Oracle Grid database designed for
use on grids of large numbers of computers. Grid computing allows
for enormously enhanced scalability, performance, versatility, integra-
tion, and automation. Oracle Database 10
Oracle Database 10
g
is the first version of Ora-
cle Database to cater to the power of grid computing. Oracle
Database 10
g
g
grid computing capacity is limited with respect to grid
