how to tune sql query in oracle

Tags: type error associated recommendation management will rom Ora no(Transferred from http://blog.csdn.net/sforiz/article/details/5345359) We have to do not only write SQL, but also to write good performance of SQL statements.(1) Select the most efficient table name order (valid only in the rule-based optimizer):The Oracle parser processes the table names in the

151510 1450 Select Se.last_name,se.salary,se.dept_id,temp.avgsalFrom S_emp SE, (Select Dept_id,avg (Salary) AvgsalFrom S_empGROUP BY dept_id) Tempwhere se.dept_id = temp.dept_idand Se.salary > temp.avgsal; 1. Query for employee information2. For example, to find out the staff information in Sector 41st, which is higher than the average salary of department 41st (this department) Select AVG (Salary), dept_idFrom S_empGroup BY DEPT_ID; Select last_nam

2 CELL This column more highlights: http://www.bianceng.cn/database/Oracle/ For example, the above query results can be achieved through the data pump query parameters, first to query deformation, into in or exists form: Sql> SELECT * from T1 2 WHERE ID in 3 (SELECT t

object in the shared pool. The next time you reference this SQL/PLSQL statement, ORACLE re-analyzes and compiles this statement.Oracle lock Table query and unlock You can solve the following problems: During batch DML operations, the program was interrupted, and a table was locked for further execution and query. Ther

Tags: blog http ar os using SP Java data onToday around 10 o'clock in the morning, boss told us that the production environment a customer in a function of the input information, the loading data is very slow situation, because the serious impact on customer use, let us hurriedly verify the reason, the leader and I based on the leadership provided by the user login system, to find the problem of the function, Select buyer and bank information after the load limit information when the leader's co

Oracle note (4) Structured Query Language (Structured Query Language): simple Query, limited Query, and data sorting 1. It is a database Query and programming Language, it is used to access data and

Tags: paging Oracle DatabaseIf you want to know the actual application of the first 10 records of Oracle query, you can click on the following article on the actual relevant operation of the correct use, there is a more perfect understanding, I hope you browse the following article will be the following is the text of the detailed content of the introduction. How

corresponding error message can usually be "ora-00900:invalid SQL statement, ora-01031:insufficient privileges or ora-00921:unexpected end of SQL command. Execute cx_Oracle.Cursor.execute (statement, [parameters], **keyword_parameters)This method can accept a single parameter--an SQL statement--that runs directly against the database. A binding variable that ass

Oracle query specified index improve query efficiency a 16 million data table--SMS Uplink table Tbl_sms_moStructure:CREATE TABLE Tbl_sms_mo(SMS_ID number,mo_id VARCHAR2 (50),MOBILE VARCHAR2 (11),Spnumber VARCHAR2 (20),Message VARCHAR2 (150),Trade_code VARCHAR2 (20),link_id VARCHAR2 (50),GATEWAY_ID number,Gateway_port number,Mo_time DATE DEFAULT sysdate);CREATE IN

the result{Echo $ ora_test [0];Echo"";} Take a complete example. If PHP version is later than 5.0, use the following function: The code is as follows: Oci_connect (username, password, dbname) The code is as follows: The code is as follows: $ Conn = oci_connect ('HR', 'HR', 'orcl '); // establish a connectionIf (! $ Conn ){$ E = oci_error ();Print htmlentities ($ e ['message']);Exit;}$ Query = 'select * FROM departments'; //

beginning of all stored procedures and triggers, and set nocount off at the end. You do not need to send the DONE_IN_PROC message to the client after executing each statement of the stored procedure and trigger.29. Avoid large transaction operations as much as possible to improve the system concurrency capability.30. Avoid returning a large amount of data to the client as much as possible. If the data volume is too large, consider whether the corresponding requirements are reasonable. Articles

1.create user username identified by password;//build username and password Oracle 2.grant CONNECT,RESOURCE,DBA to username;//authorize Grant CONNECT,RESOURCE,DBA,SYSDBA to username; 3.connect username/password//Enter. 4.select table_name,column_name from User_tab_columns where table_name= ' mview_log ';//table name in query table, field name, and so on. 5. How do I execute a script