Oracle

Set the initialization parameter remote_login_passwordfile: In the initialization parameter file of the Oracle database instance, this parameter controls the usage and status of the password file. It can have the following options: None: indicates

Improves query efficiency by specifying an index in Oracle QueryOne 16 million data table-text message upstream table tbl_sms_moStructure:Create Table tbl_sms_mo(Sms_id number,Mo_id varchar2 (50 ),Mobile varchar2 (11 ),Spnumber varchar2 (20

  Paging query statement: Select * from ( Select a. *, rownum rn from ( Select * from Table table_name) Where rownum = 20; Select * From table_name indicates the original query statement that does not flip pages. Rownu = 21 control the

Note: test is the database name, and test. DMP is the exported Oracle database backup.   Import:1. c: \ indicates that the source backup file is in the C root directory.IMP system/manager @ test file = c: \ test. dmp fromuser = System If some

1. Set Vmware Set hard disk to be greater than 20 GB; otherwise, the database fails to be created due to insufficient space. Set hard disk to 40 GB. 2. Install Oracle Linux 6 Select the following package when installing the OS: Base System>

In the financial system or other report statistics function, I want to have a lot of cases similar to the following report. With the grouping_id function, it will be easy to implement, and it will be very expensive.  

When using Oracle, we often encounter some problems that cause us to have to uninstall or reinstall the Oracle database. However, uninstalling the Oracle database is a headache. If it is not correctly uninstalled, it may cause you to have to

(I) Let's first look at two real cases from the production environment: Case 1 Case 2   (Ii) principle: Oracle does not perform accurate statistics on each of the varchar and other complex fields.Instead, perform substr (, 32) on the

  Description of the main database objects of the data Relational Database: relational model data, transaction processing relational model of shared data in 1970s IBM -- hierarchical model database, mesh model database -- relational model

After over a dozen or even 20 times of Oracle Installation, I finally installed a Complete Oracle on my computer and officially entered the Oracle learning stage. oracle caught a cold in Chinese. 1. the Installation File directory cannot contain

I. Introduction Super Large systems have the following features: 1. Generally, the number of users processed exceeds 1 million, and the number of users processed exceeds 10 million. The data volume of the database generally exceeds 1 TB; 2. The

In fact, this problem is not difficult, but it has been found on the internet for a long time. There are also between and minus. However, neither of these methods can successfully complete the paging query with sorting. Finally, we found a solution

I have been studying Oracle for a while. Today I think it is quite useful to see this summary of Oracle learning. Therefore, it leaves a taste. Tablespace Tablespace: One tablespace corresponds to multiple Data The file (physical DBF File)

Standard sqlexception provides a standardized information segment (sqlstate) and a supplier-specific information segment (errorcode ). Just like most databases and their JDBC driver implementations, oracle databases and JDBC drivers provide more

The "length" functions return the length of char. LENGTH calculates length using characters as defined by the input character set. LENGTHB uses bytes instead of characters. LENGTHC uses Unicode complete characters. leng2uses UCS2 codepoints. LENGTH4

Common Data Dictionary queries for ORACLE users View the default tablespace of the current user SQL> select username, default_tablespace from user_users; View the role of the current user SQL> select * from user_role_privs; View the system and

Converts the clobe field in oracle to the String type for ease of use.View Code 1/** 2 * convert clob type data to string type. 3 * Author: Mother Yushan 4 * Time: 2012-6-6 5 * @ param clob 6 * @ return 7 * @ throws SQLException 8 * @ throws

The first day of a month    SELECT to_date(to_char(SYSDATE,'yyyy-mm')||'-01','yyyy-mm-dd')FROM dual Sysdate is the current system time of the database server.To_char is a function that converts a date type into a date type.To_date is a function

// Add two references firstUsing System. Data. OracleClient;Using System. Data; String ConnectionString = "Data Source = sky; user = system; password = manager;"; // write the connection stringOracleConnection conn = new OracleConnection

On csdn, I also saw a post called Oracle common function 110. after a rough look, there are many data calculations, such as covariance. I don't think I have used much. I can see it today, but it is not very comprehensive. I have added it a little. I