Database Administrator

1. It is not accidental that a flute player plays well only when he goes to the playhouse of a flute player a few days ago. It is because he has really worked hard. He has downloaded many videos and tutorials on his computer! This really shocked me!

A transaction is a series of steps in a logical unit of work. Transactions are used to ensure the security of data operations. Transaction Features: Atomicity(Atomicity) Consistency(Stability,Consistency) Isolation(Isolation) Durability(Reliability)

In the morning, we performed data migration. After deploying slave2, we found that the logs of the three machines were rampant: Old slave: 2014-05-29 14:35:35 996 [Note] Slave: received end packet from server, apparent master shutdown: 2014-05-29 14

When synchronizing Oracle tables to sqlserver, this error may occur when you apply data on sqlserver. 17:20:24 WARNING OGG-01154 SQL error-2147217887 mapping APPLSYS. FND_FLEX_VALIDATION_RULES to dbo. FND_FLEX_VALIDATION_RULES [SQL error-2147217887 (

As a high-speed database, redis must have a corresponding security mechanism on the Internet for protection. 1. The safer method is to bind an IP address for control.Copy codeThe Code is as follows:Bind 127.0.0.1Allow access only through the IP

Many people have asked similar questions on the Internet: "What does it mean when someone writes an SQL statement like where 1 = 1 ?". In fact, developers generally use dynamic array SQL statements. Let's imagine the following scenario: users

Join is to splice two tables into a large table according to a public field. The left join is used to traverse the right table based on the table on the left. 1. Introduction Left join, self join SELECT * FROM test_visit t1 left join

When oracle Plsql executes update or delete, It is stuck when Plsql is stuck or when code executes SQL. When this problem occurs during development, I copied the SQL statement and executed it in plsql. The SQL spelling is correct, but the plsql

--- Create a tableCreate table TESTTABLE(Id1 VARCHAR2 (12 ),Name VARCHAR2 (32))Select t. id1, t. name from TESTTABLE tInsert into TESTTABLE (ID1, NAME)Values ('1', 'hangsan ');Insert into TESTTABLE (ID1, NAME)Values ('2', 'lisi ');Insert into

First use the official C # access component https://github.com/mongodb/mongo-csharp-driverThen, reference MongoDB after compilation. bson. dll and MongoDB. driver. dll, and declare reference to using MongoDB In the cs file. bson; using MongoDB.

PL/SQL Introduction PL/SQL is also a program Language called Procedural Language/SQL ). PL/SQL is an Oracle database pair SQL statement extension. The features of the programming language are added to the use of common SQL statements. Therefore,

Apsaradb for Memcache is a temporary key-value storage NoSQL database. In the past, it was widely used on Internet websites as a cache layer between applications and databases (it has been replaced by Redis ), it was initially developed by Danga

Zookeeper One: He backup set holds a backup of a database other than the existing 'xxdb' databaseSometime when you try to restore the backup file on an existing database and receive the following error message: Restore failed for Server'SQL Server

6.2.3 combination of and or operators In the WHERE clause, the and or operators can be used to connect multiple conditions at the same time. Of course, the and or operators can also be used at the same time. But when the and or operators exist at

String functions perform different operations on binary data, strings, and expressions. This type of function applies to CHAR, VARCHAR, BINARY, and VARBINARY data types, and data types that can be implicitly converted to CHAR or VARCHAR. I.

When I set up physical standby the day before yesterday, the previous steps were all correct (in fact, they were wrong). When I verified whether the archived logs were synchronized to the standby database, I found: ORA-16047: DGID mismatch between

The special split functions you have written are as follows:Create or replace function FN_SPLIT_STR_2 (var_str in varchar2) return varchar2/*There is a table t1 with a field named c3, which stores the location information of all stores.Now we need a

I. Master-slave Replication 1. Master-slave replication is a simple cluster technology for Database Synchronization and backup. 1.1 In the database cluster, you must clearly know who is the master server. The master server has only one. 1.2 The

I have been working on website O & M for a long time. I have been dealing with linux operating systems, so I will summarize the installation and configuration of mongodb in linux. In fact, I have also played it in windows, Which is similar! 1.

In the previous query, the result is all records in the table. If you want to only display records that meet certain conditions, you must use conditional query or a restricted query. Basic Syntax of conditional query: SELECT * | (specific column