Database Administrator

Oracle's use of null in not in In the past, I also summarized some Oracle NULL problems. It happened that I saw another point that I didn't find before when I was reading the book, that is the question of using null in not in. SQL> select * from

DataGuard slave database deletes applied logs The company set up a slave uard. At the beginning, it did not pay attention to the management of archiving logs in the slave database. After the system was running for a while, it was found that the

MangoDB creates, updates, and deletes documents Preface The previous article has a general understanding of the basic operations of MongoDB. In this article, I will explain in detail how to create, update, and delete MangoDB. Related reading: and 1.

Current online redo logfile loss Handling Method We have previously performed a recovery drill after the rm-rf operation, and there is no backup. Today, before performing destructive operations, we made an rman full backup, and then deleted all

Mybatis dynamically transfers table names (also applies to dynamically transfers table fields) and mybatis Fields // Set the name of the map parameter, innerTable, and outTable. Public String sendDetail (){Pager = getStartPager ();If (null! = Msg &

The Propagation Behavior and isolation level of Spring transactions, and the spring transaction isolation level 1. propagation of transactions In the use of transactions, the most widely used Propagation Behavior is require. In most mis systems, you

Oracle: view the table space where the user is located; oracle: view the user's location View the tablespace of the current user select username,default_tablespace from user_users; Modify the user's default tablespace Alter user Username default

SQL advanced (7) Date function, sqldate FunctionSQL advanced (7) Date function SQL Date when we process a Date, the most difficult task is to ensure that the format of the inserted Date matches the format of the Date column in the database.As long

MySQL lock Blocking analysis, mysql lock Blocking During routine maintenance, threads are often blocked, resulting in slow database response. Let's take a look at how to obtain which thread causes blocking. Blog: http://blog.csdn.net/hw_libo/article/

Oracle _ Study Notes: oracle4.09.05, oracle_2014.09.05Oracle Study Notes Test Database Configuration Information Global Database Name: xiuhao system identifier (SID): xiuhao server parameter file name: c: \ oracle \ dbs \ spfilexiuhao. oradatabase

In linux, databases are regularly backed up after time. bakfordatabase.shmysqldump -uuser -ppassword database>folder/`date "+%Y-%m-%d~%H-%M-%S"`.sql Back up a mysql database in a specified time Mongodump-d database-o folder' back up mongodb

Detailed process of user interaction with Oracle DB, process of user oracledb Interaction with Oracle DBThe following example describes the Oracle database operations at the most basic level. This example shows an Oracle DB configuration in which

Install Oracle Enterprise Cloud Control 12c and oracle12c in Linux 6.3 The installation of Oracle enterprise cloud control 12c is a complicated process, because it depends on Kernel El database and Oracle Weblogic. Now Oracle has integrated Weblogic

Mysql exports the queried data as excel and mysqlexcel Now you need to export some data from the mysql database to excel and print it. In fact, it is very easy to implement the above requirements, as long as you write the SQL statement, and then

Connection sequence in the WHERE clause of Oracle performance optimization learning notes, oracle Performance Optimization ORACLE uses the bottom-up sequence to parse the WHERE clause. According to this principle, the join between tables must be

The use of views in SQL (simple views) is suitable for entry-level SQL views. Creating a view can better call data from one database to another (for example, transferring data from database 209 to database 205) Example: Database 209 has different

Cannot set user id: Resource temporarily unavailable, cannotsetuserid A while ago, Infra reported that the database server could not be connected through putty and SecureCRT. The error message is Resource temporarily unavailable. Since there are

Backup mysql for xtrabackup with xbstream and lz4, xtrabackupxbstream You need to temporarily add an instance for mysql. Using xtrabackup is the easiest and quickest. On an existing data node: /Home/work/app/xtrabackup-2.2.3/innobackupex --

MYSQL uses select to query the record method of a field that contains strings separated by commas (,). First, create a string separated by commas. Create table test (id int (6) not null AUTO_INCREMENT, primary key (id), pname VARCHAR (20) not null,

[Sqlite] --> data migration and backup -- from earlier versions 3.6.2 to later versions 3.8.6 and 3.6.23.8.6Data Migration 1. Use the. dump command Command help prompt . Dump? TABLE? ... Dump the database in an SQL text format If TABLE specified,