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This article mainly explains "what are the commonly used Oracle statements in performance testing". The content of the explanation is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought. Let's study and learn what Oracle statements are commonly used in performance testing.

The main purpose of oracle performance testing is to simulate a large number of sql statement operations to pressurize the database server. Before testing, you need to prepare the following sql statements to be simulated, test scripts, and prepare the test control machine, test pressure machine, and tested database server.

Advantages and disadvantages of Oracle database performance

Advantages

1. Able to run on all major platforms (including windows). All industry standards are fully supported. Adopt a completely open strategy. Enables customers to choose the most appropriate solution. Full support for developers.

2. Parallel servers extend the ability of windownt by making a group of nodes share the work in the same cluster, and provide high availability and high scalability cluster solutions.

3. If windowsNT can not meet the needs, users can move the database to UNIX.

4. In terms of security, the performance is the highest.

5. Client support and application mode, multi-level network computing, supporting a variety of industrial standards, network customer connection requirements such as ODBC,JDBC,OCI can be used, and the database can be constructed according to the actual system requirements.

6. Adopt the standard SQL structured query language.

7. Rich development tools covering all stages of the development cycle.

8. Support large databases, data types support numbers, characters, binary data up to 2GB, and provide data support for object-oriented storage of the database.

9. Development tools with the fourth generation language (SQL*FORMS, SQL*REPORTS, SQL*MENU, etc.).

10. With character interface and graphical interface, it is easy to develop.

11. Control user rights through SQL*DBA, provide data protection function, monitor the running status of the database, and adjust the size of the data buffer.

12. Query function of distributed optimization.

13. It has transparent data and network, and supports heterogeneous networks and heterogeneous database systems. Dynamic data slicing technology is used in parallel processing.

14. Support client / server architecture and hybrid architecture (centralized, distributed, client / server).

15. Realize the means of two-stage submission and multi-clue query.

16. Data security protection measures: there is no read lock, and snapshot SNAP is adopted to completely eliminate distributed read-write conflicts. Automatically detect deadlocks and conflicts and resolve them.

17. The data security level is C2 (the highest level).

18. The database internal model supports multi-byte code system and multi-language coding.

19. It has manufacturing system-oriented management information system and financial system application system.

20. WORKGROUP/2000 has ORACLE7WORKGROUP server and POWER OBJECTS (graphic development environment), which supports OS/2, UNIX and WINDOWS/NT platforms.

21. The sales share in China accounts for more than 50%.

Shortcoming

1. Management and maintenance is more troublesome.

2. It is troublesome to reply after a database crash, because he keeps a lot of things in memory.

3. Database connections should be slow, and it is best to use connection pooling

4. Large objects are not easy to use, and the vchar2 field is too short to be used.

5. The work of the administrator is annoying, and experience is very important.

6. The requirement of hardware is very high.

Commonly used Oracle statements in performance testing

Displays the current number of connections to the database:

Selectcount (*) from v$process

Displays the maximum number of database connections:

Selectvalue from v$parameter where name = 'processes'

Modify the maximum number of Oracle connections:

Alter systemset processes = 300scope = spfile

Displays the current number of session connections:

Selectcount (*) fromv$session

See which users are currently using the data:

SELECT osuser,a.username,cpu_time/executions/1000000 | | 'sql_fulltext,machine fromv$session, sql_fulltext,machine fromv$session a, v$sqlarea b where a.sql_address = b.address order by cpu_time/executionsdesc

Check the SGA in the database:

System globalarea (SGA), system globalarea (PGA)

Check the number of connections to all machines connected to oracle:

Selectmachine,count (*) fromv$session groupbymachine

Check the number of connections and status of all machines connected to oracle:

Selectmachine,status,count (*) fromv$session groupbymachine,status orderbystatus

Oracle 11g sets automatic memory management:

View SQL Top 5 that consumes the most disk reads:

Selectdisk_reads,sql_text,SQL_FULLTEXT

From (selectsql_text,disk_reads,SQL_FULLTEXT

Dense_rank () over

(order by disk_reads desc) disk_reads_rank

From v$sql)

Wheredisk_reads_rank

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