DBMS_COMPRESSION is a package used to manage the Oracle Database table compression feature. This feature lets you compresses data by eliminating duplicate values in disk pages. As database grows in size, table compression saves resources, not only disk storage but also reduces memory use in the buffer cache. First introduced in 11g R2, this package has been evolving, and some very useful enhancements were introduced now in 12c release.
PL/SQL applications consist – generally – of many procedures, functions and packages. A group of them can be invoked directly by applications as entry points of their user requirements while others are invoked by other packages as part of application business design.
Before Oracle 12c – in terms of database security – there was no difference between these two groups, and a granted user was able to execute any of these many units irrestrictively.
Oracle 12c introduces a new optional ACCESSIBLE BY clause that enables you to prevent package executions from outside the business logic, specifying a whitelist of predefined known elements that can only access a specific PL/SQL unit.
Introduced in Oracle 12c release, it is possible to create partial indexes on a partitioned table. While a full index includes all partitions in a given table, a partial index just includes only partitions which are mark to be indexed during table creation process. This new 12c feature provides more flexibility with index creation and reduce storage utilization.
Oracle 12c introduced a new utility which replaces the need to run post installation SQL scripts after a database patch is applied.
This new utility is called “Datapatch” and it is shipped with 12c binaries as a component of OPatch distribution.
“Datapatch” is very useful in multitenant environments where multiple PDBs (Pluggable Databases) must be patched together.
Oracle Database 12c provides a set of security features that can be used to manage several and diverse topics such as authentication, privileges and roles, application security, encryption, network traffic, and auditing. This blog post will address the new READ and READ ANY TABLE object privileges introduced in Oracle database 12c.