Database Administrator

Differences between sysdba, sysoper, and dba For sysdba, sysoper, and dba, many terms may be used at work. If the environment is a server, sysdba may be frequently used. DBAs are required permissions for database maintenance. The official Oracle

About the locks in the MySQL InnoDB Storage Engine Recently, I encountered many lock problems. After solving these problems, I carefully read the books about locks and sorted them out as follows: 1. Lock type The Innodb Storage engine implements the

MySQL master-slave Replication The principle of MySQL master-slave replication is the same as that of MySQL master-slave replication, but slave databases cannot be used for write operations, therefore, some parameter configurations may be different

NewSQL database VoltDB features, newsql database voltdb VoltDB is a revolutionary new database product called NewSQL database. It is based on H-Store and claims to be 45 times higher than the current throughput of database products, and has high

GPDB parallel loading test and gpdb parallel loadingTest File Information 10G Dec 12 14:10 A111G Dec 12 14:32 A210G Dec 12 14:10 B111G Dec 12 14:35 B2GPFDIST solution 1 Single Server drop table if exists host_1;drop EXTERNAL TABLE if exists exttable_

MongoDB entry-add, delete, modify, and query-mongodb entry-add, delete Mongodb has been successfully started in the previous blog: continue. Open another cmd and enter the [mongo] command to open the shell, that is, the mongodb client. The "test"

[Oracle] Chapter 2 common operations, Chapter 2 of oracle Chapter 2 common ORACLE operations Modify the column information in the table: Alter table vendor_master modify (vencode varchar (20 )); Add a default value constraint to the column in the

Test your understanding of MySQL transactions and isolation levels. I have written an article titled MySQL InnoDB Transaction isolation level and dirty read, Repeatable read, phantom

Mysql database server adjustment, mysql Database Server Make a database server adjustment to the customer the day before yesterday, discard the previous host, promote the master from the database, and then add the new slave. Here, record the

Database practical Script 1 --- query the table names with data in the database and the number of rows in the table, 1 --- number of rows Create table # Temp(Name varchar (30 ),Num int) Declare @ Name varchar (30)Declare @ SQL varchar (1000)

Colored SQL -- How to force the AWR to capture a specified SQL even if it is not the top one, SQL -- howawrThis new feature doesn' t paint the SQL statement in color; rather, it sort of marks it as "important ."Suppose you are troubleshooting a

SQL like usage fuzzy query and SQL fuzzy query Fuzzy query: References: http://www.w3school.com.cn/ SQL/SQL _wildcards.asp When searching for data in a database, you can use the SQL wildcard.SQL wildcard Like When searching for data in a database,

The lock request timeout period has been exceeded. (Microsoft SQL Server, error: 1222), sql1222 When operating the SQL Server database, the following problem occurs: the lock request timeout period has been exceeded. (Microsoft SQL Server, error: 12

Mysql installation (Using Generic Binaries), genericbinaries Mysql is Mysql 5.6.21 and is installed in common Linux. That is, most Linux platforms can install Mysql in this way. 1. Installation Steps 1. installation environment 1) Centos 7.0.1406 X86

An example of SQL SERVER database attack Recently, it was found that the SERVER on the internet is inexplicably restarted. This SERVER currently mainly starts the IIS and SQL SERVER services. Remote Login, found that the system reaction is slow,

Hive non-interactive mode and hive Mode Run $ HIVE_HOME/bin/hive on a linux terminal to enter the interaction mode; $ HIVE_HOME/bin/hive-e or-f is in non-interactive mode. 1. Execute HQL statements in non-interactive mode $HIVE_HOME/bin/hive -e

The agent slave Database Host cannot be found when the slave database is created in EM12c, And the em12cagent Symptom:When you use EM12cR4 to create a slave database, you cannot find the slave Database Host, but the slave Database Host

XML parsing --- dom parsing and sax parsing, xml --- domsax Parsing Currently, two methods are used for XML parsing: 1. dom parsing: (Document Object Model, that is, Document Object Model) is a method recommended by W3C for parsing XML. Use dom to

Difference between % TYPE and % ROWTYPE in PL/SQL, % type % rowtype % TYPE: Defines a variable. Its data type is the same as that of a defined data variable or the data type of a column in a database table.In this case, % TYPE can be used.The

Mysql inserts data in batches using stored procedures and mysql stored procedures Recently, we need to test the performance of adding, deleting, modifying, and querying more than data records in a single mysql table. Because there is no ready-made