Comparison of database management functions between Oracle11g and Oracle12c

Oracle is a world-famous relational database management system, and its different versions provide different functions and performance optimization. This article will compare the database management functions of Oracle 11g and Oracle 12c, and provide some specific code examples to illustrate their differences.

1. Comparison of storage management functions

1.1 Data file management

In Oracle 11g, we need to manually add and expand the size of data files, for example:

ALTER DATABASE DATAFILE 'datafile01.dbf' RESIZE 100M;

In Oracle 12c, the automatic data file management function is introduced, which can dynamically adjust the size of data files as needed, which is more convenient:

ALTER DATABASE AUTOEXTEND ON;

1.2 Column data storage

Oracle 12c Column storage technology has been introduced, which will be more efficient when processing large amounts of data, such as creating column storage tables:

CREATE TABLE employees (
    emp_id NUMBER,
    emp_name VARCHAR2(50),
    emp_salary NUMBER
) SEGMENT CREATION IMMEDIATE
COLUMN STORE COMPRESS FOR QUERY LOW;

2. Comparison of performance optimization functions

2.1 Automatic optimizer

Oracle 12c introduced an automatic optimizer that can select the optimal execution plan based on the actual data volume and query plan, thereby improving query performance, such as enabling the automatic optimizer function:

ALTER SYSTEM SET OPTIMIZER_MODE='ALL_ROWS';

2.2 Parallel query

Parallel queries can be used in Oracle 11g to improve query efficiency, for example:

SELECT /*+ PARALLEL(employees, 4) */ * FROM employees;

In Oracle 12c, through the automatic parallel query function, the system can automatically decide whether to use parallel queries, which reduces management staff workload.

3. Comparison of security management functions

3.1 Data encryption

The transparent data encryption function was introduced in Oracle 12c, which can perform real-time encryption and protection of data, such as sensitive data Encryption:

ALTER TABLE employees MODIFY emp_salary ENCRYPT;

3.2 Data Masking

Oracle 12c also adds a data masking function that can blur sensitive data to protect privacy, such as:

SELECT DBMS_REDACT.REDACT('employees', 'emp_name', 'policy_name') FROM employees;

In summary Compared with Oracle 11g, Oracle 12c has significant improvements and enhancements in storage management, performance optimization and security management. Through the above comparison and code examples, we can more intuitively understand the differences in database management functions between the two versions, helping us better choose the version that suits our needs.

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