Database Administrator

By default, for security reasons, the MySQL database in Linux shields remote access. However, in many cases, you need to access the remote database server at home or from a web application, which is quite troublesome. Step 1: Activate network

Use occi to connect to Oracle in Linux without installing a client1. Assume that you have successfully installed the oracle10g and Eclipse C ++ environments.2. Replace libocci. so.10.1 and libocci10.a in the "opt/.../db_1/lib" path. (First download

After installing the OOracle software on the Linux platform, you do not need to use dbca to create a database, but manually create a database. The main purpose is to understand the operations performed during database creation. 1. First set the SID

I have always wanted to take a good look at Oracle, but now the item is about oracle Security. So, take a moment to sort it out. Although it is impossible to fully understand oracle, but it is better to do it than not. I. ORACLE instances　　1. ORACLE

MongoDB is a scalable and high-performance next-generation database. Data in MongoDB is stored as documents, so that complex relationships can be expressed in a single data object. A document may consist of the following parts: an independent basic

For example, update table1 t1 set t1.name= (Select t2.name from table2 t2 where t2.age = 20) Cause of error: the subquery contains more than one record. If you want to update data in batches, You can nest the data, for example, the following SQL

In data development applications, data needs to be sorted in most cases. However, in Oracle databases, there is a NULL value ). If some values in a column are empty, if this column is sorted, the rows with null values are sorted at the end, for

1. OracleThe role of Package:   It can simplify application design, improve application performance, hide information, and overload subprograms. 2. Functions in ORACLE, Package, packageThe differences between bodies and procedure are the

Database environment: Oracle 9i HOST: AIX 5.3 Symptom: It is too slow to connect to the database. You can use topas to check the resource usage of the host. Everything is normal. The connection from the local database to itself will be slow as

Oracle has db_block_size and the operating system also has block size. The following is a brief introduction. AIX: View the size of each block in the AIX operating system: # Lsfs-q/u01 Name Nodename Mount Pt VFS Size Options Auto

LpadIn Oracle/PLSQL, the lpad function fills the string on the left with some specific characters,The syntax format is as follows:Lpad (string1, padded_length, [pad_string])String1 is the string to be pastedPadded_length is the number of returned

Create type char_table is table of varchar2 (4000); -- create a custom type script Create or replace function split_string (pi_str in varchar2, pi_separator in varchar2) -- create a functionReturn char_tableIsV_char_table char_table;-- Create type

When you use Database Link to integrate a remote Database, the system returns the ORA-22992 error when querying Blob fields from the remote Database. Some people use materialized views to solve this problem, but the synchronization mechanism of

Use of Oracle Flashback table Oracle ensures that recyclebin is enabled SQL> show parameter recyclebin NAME TYPE VALUE-----------------------------------------------------------------------------Recyclebin string ON creates a table SQL> create table

We have published three articles in the first, second, and third articles in one of the basic questions and answers for Linux interviews, which are well received by readers. At the same time, we have received feedback. Some readers hope that this

In 11g, Oracle introduced a new feature: adaptive cursor sharing. This feature is mainly used to improve the execution plan of SQL statements with variable binding. It also causes SQL statements with variable binding to generate multiple cursors. In

This article introduces flume data insert hdfs and common directory (), this article continues to introduce flume-ng to insert data into the hbase-0.96.0. First, modify the flume-node.conf file in the conf directory under the flume folder in node

A few days ago, the system was migrated from Oracle to mysql. Many statements are relatively simple, that is, some function modifications, such as to-date. But there are also a few tricky ones, which are recorded here 1. row_number () over

The day before yesterday, the deployment and implementation company xx production center entered a set of DG databases, but before that, one of the primary was a test machine before I N. I remember that I installed version 11.2g 03 in the form of

Oracle Server: Select * from NLS_database_PARAMETERS where parameter like '% CHARACTERSET % ';PARAMETER VALUE----------------------------------------------------------------------NLS_CHARACTERSET WE8MSWIN1252NLS_NCHAR_CHARACTERSET AL16UTF16 Table t1: