Database Administrator

Test MySQL performance using sysbench 0.5 In view of my recent interest and passion for OpenStack, I want to ensure that I can perform proper system performance evaluations. I mainly started to switch to sysbench because it brings a series of tests

Oracle CRS-0184 cannot talk to crs daemon Oracle 11g rac crs process restart Error 1. The above error occurs when you create a rac cluster. Delete the/etc/oracle/scls_scr/rac1/oracle/cssfatal file on node1.

PostgreSQL9 PPAS9 stream replication Configuration Set up a stream replication cluster for PostgreSQL. Host: PPAS1 PPAS2 1Install PPAS 9.0[Root @ ppas1 ~] # Setenforce 0[Root @ ppas1 ~] # Ppasmeta-9.0.4.14-linux-x64.run-All installation [Root @ ppas1

Oracle Database query performance optimization Querying, adding, modifying, and deleting databases are important factors that affect web application performance indicators. The following are some common suggestions to improve query performance. 1.

MongoDB operating factors and data models The data of the MongoDB modeling application depends on the data itself, which is also related to the characteristics of MongoDB. For example, different data models may increase the query efficiency of

The mysql transaction rollback is invalid. A strange thing happened to the Payment Service recently. When a transaction fails, you call rollback and find that only the last SQL statement is rolled back. After a long time of development check, it

Oracle NLS_DATE_FORMAT, nls_date_format Nls_date_format is used to modify the date format. Modify the session level: alter session set nls_date_format = 'yyyy-mm-dd hh24: mi: ss' Modify the Registry in windows: HKEY_LOCAL_MACHINE.SOFTWARE.ORACLE.

How does Hibernate manipulate Clob data? hibernateclob In POJO, a large String object can be declared as a java. lang. String or java. SQL. Clob type. When a program loads Clob data from a database, it only loads a logical pointer of Clob data. You

Primary Key considerations for Database Design According to the second paradigm, primary keys are required. The primary key is still unique, and the primary key is also referenced as a foreign key to establish the relationship between the table and

Git is used in linux and Gitlinux * Initialize the git repository and use the git init command * Add a file to the git repository in two steps: 1. Use git add filename. You can use it multiple times and add multiple files to the temporary storage

Linux/centos oracle10g control connection IP address, centosoracle10gOracle controls the IP address of the connected database Simply set allowed IP addresses and prohibited IP addresses In 9i and later, modifying sqlnet. ora is actually the best and

Oralce SQL creates the calendar information for a specified period of time, oralcesql The creation start time is 2010 and the end time is 2100. Create table temp_calendar as selectMin (to_char (day, 'yyyymm') month, To_char (min (decode (weekday, 1

Powerdesigner converts PDM to MYSQl databases, powerdesignerpdm Use PowerDesigner to design and build a MySQL database1. Create a database creation script using PowerDesigner1. Design CDM (Conceptual Data Model)2. Select Tools> Generate Physical

MySQL advanced technology-transaction processing and lock, mysql Transaction ProcessingMySQL advanced technology-transaction processing and lockHow does mysql lock a row of data with transactions and locks so that two users are not allowed to read a

Basic MySQL-basic database operations and basic mysql operations 1. Delete the database drop database name; Mysql> drop database test; Delete database mode 2. create DATABASE name; Mysql> create database test; In Windows and Linux, database names

Insert data to the database (ORACLE) through excel, exceloracle We all know that PL/SQL can copy data to excel, and we can also insert data to the database through excel. The following is a simple example and example. First, create a table named

Tranlogoptions rawdeviceoffset, tranlogoptions Today, we will introduce the tranlogoptions rawdeviceoffset parameter in ogg. this parameter is not described in the ogg official documentation. This parameter is used when you use a bare device. Let's

MongoDB spatial location (point) and distance retrieval, mongodb Retrieval MongoDB 2.6-based GeoJSON format {"Type": "Point", "coordinates": [lon (longitude), lat (latitude)]} Test Data Db. point. test. insert ({"address": "Nanjing lukou

After the ib_logfile and ibdata1 parameters in MySQL are modified 1. Environment Description RHEL 6.4 x86_64 + MySQL 5.5.37 and MySQL 5.6.19 Blog: http://blog.csdn.net/hw_libo/article/details/39215723 2. Case: The redo log file (ib_logfile) size

Understanding of the deviation of the fromuser parameter in imp, impfromuser There is always a problem when importing dump files in the past two days. Symptom: 1. Run: imp xyz/xxx file = test. dmp log = imp_test.log fromuser = test1 touser =