Database Administrator

Oracle copy column Value Requirement: Add a field to an existing table in the test environment, and manually add data to this column of some data in the table, now you want to add this field in the formal environment and copy the existing values in

Install MySQL5.6 in Linux compilation and modify Character Set Environment preparation:After mysql5.5, The./configure compilation method will be changed to the cmake tool for compilation.Install the dependency package: yum install-y cmake gcc-c ++

Cleaning temporary tablespace in Oracle Oracle temporary tablespace is mainly used to query and store some buffer data. Temporary tablespace consumption is mainly caused by sorting the intermediate query results. The main functions of temporary

MD5 encryption in Oracle Because MD5 encryption is used, I searched the internet for relevant information and studied it carefully. Its core is the MD5-encoded data packet function: DBMS_OBFUSCATION_TOOLKIT.MD5, which involves the RAW type, which is

PostgreSQL checkpoint Principle Let's talk about PostgreSQL's checkpoint principle today. The checkpoint function is available in popular databases. Such as Oracle and MySQL, especially the implementation of the checkpoint function in Oracle. Oracle

How to do the truncate operation for a primary table associated with a foreign key The primary and Foreign keys are mandatory associations between two tables provided by the database. They can also be implemented at the application layer.  

Oracle creates dblink and scheduled tasks, and oracle creates dblink Recently, we are working on a task, specifically, to regularly insert data to the middle table of another user's database. The first thing we need to do is create an oracle dblink

A problem that requires attention when the keywords in the Multi-Table connection query are incorrect. Author: iamlaosong In multi-table join queries, the most common thing is inner join, and the most commonly used in inner join is equivalent join.

TNS-03505 name cannot be resolved, tns-03505 name resolved TNS-03505 name can not resolve the problem Phenomenon: [oracle@db01 admin]$ tnsping priTNS Ping Utility for Linux: Version 11.2.0.4.0 - Production on 15-JUN-2015 21:57:52Copyright (c) 1997, 2

ORA-19706: invalid SCN, ora-19706scn Today's site dblink reported ORA-19706: invalid SCN, database versions are 11.2.0.4. After checking metalink, the two databases will synchronize the scn number when accessing through dblink. The result of SCN

[Oracle] First Trial of Oracle and first trial of oracle I don't know how much you know about Oracle? Is it just to the extent that it can be used. In this case, I will follow my steps to learn more about Oracle and unveil the secrets of

MySQL programming on linux (V): MySQL permission management and mysql permission management[Copyright statement: respect originality. For reprinted content, Please retain the Source: blog.csdn.net/shallnet. this document is only intended for study

MySQL uses cmd to query Chinese garbled characters and mysqlcmd to query garbled characters When viewing the MYSQL database table, CMD finds that Chinese data cannot be inserted and the Chinese characters are garbled. Method: Find the my. ini file

Write the redis script and the redis script togetherI. redis script Environment To write redis scripts, we should first set up its script environment. Redis uses lua as its scripting language. Therefore, building a lua environment becomes the first

Extended map and extended map of associated queries select one.*,tw.id sid,tw.catlevel slevel,tw.name sname,tw.code scode,thr.id tid,thr.catlevel tlevel,thr.name as tname, thr.code as tcode from tb_sort one join tb_sort tw on

Why does the Database need Implict Commit (implicit Commit transaction), implictcommit First look at an SQL statement. What do you think is the output of the last SQL statement? SET AUTOCOMMIT = 1;BEGIN;INSERT INTO t1 VALUES (1);CREATE TABLE t2 (pk

How to Use union, except t, and INTERSECT in SQL, unionintersectThere is a reason to put these three together, because they all operate on two or more result sets, and these result sets have the following restrictions:The columns and columns in all

Simple SQL partially strengthens exercise questions, simple SQL strengthens exercise questions Simple query of some SQL exercises -- Select * from emp where deptno = 30 for all employees in department 30; -- list the names, numbers, and

ORACLE 11G is imported from instance 1 full database to instance 2 on the same linux server, oracle11g Export command in the early stage: [root@powerlong4 ~]# su - oracle[oracle@powerlong4 ~]$ export ORACLE_SID=pt1;[oracle@powerlong4 ~]$ expdp

Use PLSQL to sort strings, and plsql to sort strings1. Create a Function program Create or replace function sort_string (p_string IN VARCHAR2) RETURN VARCHAR2 is type typ_rec is record (letter VARCHAR2 (256), -- RECORD letter seq PLS_INTEGER --