They can create tables, views, and other database objects. It is also possible to import, export and view table data. The users can write SQL queries and execute them to perform operations on the database objects. Also, in this, it is possible to generate reports. The Oracle Database 12c Release 1 provides in-memory column store. It is an optional add-on that provides in-memory capabilities. The in-memory option provides real-time analysis. One major advantage of this Oracle version is that it enables the users to transit to the cloud more easily.
Moreover, it follows a multitenant architecture. Invisible Indexes in Oracle Database 11g Release 1 - Take control of the indexes available to the optimizer by using invisible indexes in 11g. SQL Access Advisor in Oracle Database 11g Release 1 - Use this advisor to get suggestions for indexes, materialized views and partitioning schemes to improve system performance.
Statistics Collection Enhancements in Oracle Database 11g Release 1 - Provide the optimizer with additional selectivity information and avoid new statistics adversely affecting performance. Temporary Tablespace Enhancements in Oracle Database 11g Release 1 - Take advantage of better visibility and management of temporary tablespaces usage in 11g.
Upgrading to Oracle Database 11g - This article provides a brief overview of the areas involved in upgrading existing databases to Oracle 11g. Automatic Subprogram Inlining in Oracle Database 11g Release 1 - Automatic subprogram inlining can reduce the overheads associated with calling subprograms, whilst leaving your original source code in its normal modular state.
That said, it is inevitable that support resources will become more focused on the newer current releases over time. It is said that 18c will take the position as a refresh to The change in the release cycle puts Oracle in position with the rest of the industry that uses the year of the release as the version number.
Therefore, preventing the likelihood human intervention or any malicious behavior, virtually eliminating human error, further helping reduce security risks.
All those kinds of things. For example, after an application queries a table, the database may use an index to find the requested rows, read the data into memory, and perform many other steps before returning a result to the user.
The RDBMS stores and retrieves data so that physical operations are transparent to database applications. Oracle Database has extended the relational model to an object-relational model, making it possible to store complex business models in a relational database.
The current version of Oracle Database is the result of over 30 years of innovative development. Highlights in the evolution of Oracle Database include the following:. Oracle Version 3, released in , was the first relational database to run on mainframes, minicomputers, and PCs.
The database was written in C, enabling the database to be ported to multiple platforms. Version 4 introduced multiversion read consistency. Oracle8 was released in as the object-relational database, supporting many new data types. Additionally, Oracle8 supported partitioning of large tables. Oracle8 i Database, released in , provided native support for internet protocols and server-side support for Java.
Oracle8 i was designed for internet computing, enabling the database to be deployed in a multitier environment. Oracle9 i Database introduced Oracle RAC in , enabling multiple instances to access a single database simultaneously. Oracle Database 10 g introduced grid computing in This release enabled organizations to virtualize computing resources by building a grid infrastructure based on low-cost commodity servers.
A key goal was to make the database self-managing and self-tuning. Oracle Database 11 g , released in , introduced a host of new features that enable administrators and developers to adapt quickly to changing business requirements. The key to adaptability is simplifying the information infrastructure by consolidating information and using automation wherever possible. One characteristic of an RDBMS is the independence of physical data storage from logical data structures.
In Oracle Database, a database schema is a collection of logical data structures, or schema objects. A database schema is owned by a database user and has the same name as the user name.
Schema objects are user-created structures that directly refer to the data in the database. The database supports many types of schema objects, the most important of which are tables and indexes. A table describes an entity such as employees. You define a table with a table name, such as employees , and set of columns. In general, you give each column a name, a data type , and a width when you create the table. A table is a set of rows. A column identifies an attribute of the entity described by the table, whereas a row identifies an instance of the entity.
For example, attributes of the employees entity correspond to columns for employee ID and last name. A row identifies a specific employee. You can optionally specify rules for each column of a table. These rules are called integrity constraints.
This constraint forces the column to contain a value in every row. An index is an optional data structure that you can create on one or more columns of a table.
Indexes can increase the performance of data retrieval. When processing a request, the database can use available indexes to locate the requested rows efficiently.
Indexes are useful when applications often query a specific row or range of rows. Indexes are logically and physically independent of the data. Thus, you can drop and create indexes with no effect on the tables or other indexes. All applications continue to function after you drop an index.
A general requirement for a DBMS is to adhere to accepted industry standards for a data access language. In contrast to procedural languages such as C, which describe how things should be done, SQL is nonprocedural and describes what should be done. Users specify the result that they want for example, the names of current employees , not how to derive it. All operations on the data in an Oracle database are performed using SQL statements.
For example, you use SQL to create tables and query and modify data in tables. A SQL statement can be thought of as a very simple, but powerful, computer program or instruction. SQL unifies the preceding tasks in one consistent language.
The principal benefit of server-side programming is that built-in functionality can be deployed anywhere. Oracle Database can also store program units written in Java. A Java stored procedure is a Java method published to SQL and stored in the database for general use. Oracle Database is designed as a multiuser database. The database must ensure that multiple users can work concurrently without corrupting one another's data.
An RDBMS must be able to group SQL statements so that they are either all committed , which means they are applied to the database, or all rolled back , which means they are undone. A transaction is a logical, atomic unit of work that contains one or more SQL statements. An illustration of the need for transactions is a funds transfer from a savings account to a checking account. The transfer consists of the following separate operations:. Oracle Database guarantees that all three operations succeed or fail as a unit.
For example, if a hardware failure prevents a statement in the transaction from executing, then the other statements must be rolled back. Transactions are one of the features that sets Oracle Database apart from a file system. If you perform an atomic operation that updates several files, and if the system fails halfway through, then the files will not be consistent. In contrast, a transaction moves an Oracle database from one consistent state to another. The basic principle of a transaction is "all or nothing": an atomic operation succeeds or fails as a whole.
A requirement of a multiuser RDBMS is the control of concurrency , which is the simultaneous access of the same data by multiple users. Without concurrency controls, users could change data improperly, compromising data integrity. For example, one user could update a row while a different user simultaneously updates it. If multiple users access the same data, then one way of managing concurrency is to make users wait. However, the goal of a DBMS is to reduce wait time so it is either nonexistent or negligible.
All SQL statements that modify data must proceed with as little interference as possible. Destructive interactions, which are interactions that incorrectly update data or alter underlying data structures, must be avoided. Oracle Database uses locks to control concurrent access to data. A lock is a mechanism that prevents destructive interaction between transactions accessing a shared resource. Locks help ensure data integrity while allowing maximum concurrent access to data.
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