Database Administrator

Condition: In the same version of the operating system, copying a database involves copying software and database files as follows:1. Package files in the Oracle Installation Directory of the source database:Js_znjh_1./app/oracle $ tar cvf

ASM is an outstanding new feature in Oracle Database 10 Gb. It provides file system, logical volume manager, software RAID and other services in a platform-independent manner. ASM can strip and mirror disks, so as to add or remove disks and

Before giving you a detailed introduction to Oracle Hints, let's first understand what Oracle Hints is, and then give a comprehensive introduction to Oracle Hints, hoping to be useful to you. The cost-based optimizer is very intelligent. In most

1. Install RedHat Enterprise Client 5.3 Now the Redhat installation process has been very user-friendly, and the entire installation process is not too complicated. During the installation process, the most important thing to note is the Linux swap

Related reading: Install and start MongoDB in Linux Advanced query example in MongoDB MongoDB Java API for insert and single collection basic query examples Query operations under MongoDB (corresponding to Java API query operations) [Root @

Install Oracle 11gR2 Ubuntu Linux 11.04 (64-bit)Version C-update May 31,201 1Author: DudeNote:The following instructions work for Oracle 11gR2 11.2.0.1 (x86_64) and have also been tested with an Out-of-Place upgrade to 11.2.0.2. just select the

Java uses JDBC to connect to Oracle and MSSQL instances: ImportJava. SQL .*; Public ClassTestJDBC { Public Static VoidMain (String [] args ){ Connection oracle_conn =Null; Statement oracle_stmt =Null; ResultSet oracle_rs =Null;

Background: Because the Linux server used for development is in a relatively closed environment, only port 22 is accessed through SSH. Therefore, putty is used to create an SSH forwarding, which maps the port 27018 of the local machine to the remote

In fact, MapReduce in MongoDB is more similar to GroupBy in relational databases. Just after doing this experiment, the GroupBy (MapReduce) for large data volumes is still ideal, generating million 3-bit random strings For(VarI = 0; I {  VarX ="

Skip the theoretical things and go to the web page to introduce automatic sharding. Or test with million data Insert million pieces of data to a database without sharding. Data storage: Performance_^ [root @:/usr/local/mongodb/data/mongodb/test] #

I installed it on RHEL6 32-bit. Use the gnome gui to install all the Development kits in Development Tools, or quickly install them and build a local yum source and then use the group for installation. It is worth noting that swap requires at least 3

Install ODBC in Linux 1. Modify the odbc. ini and odbcinst. ini files in the/etc directory.The odbc. ini file mainly configures database connections.Configure the database driver file in odbcinst. ini Root @ wwww.bkjia.com:/etc # more odbc.

Oracle error message ORA-28001: the password has expired, According to the survey, the new features of Oracle 11G are caused. The default password expiration limit for Oracle 11G users is 180 days. If the user password is not modified for more than

Oralce has a special "Take care" of the position after sorting the NULL value, which is the "nulls first" and "nulls last" options, with this option, you can forcibly specify the position where the NULL value appears in SQL sorting (whether it is

Move data objects between tablespaces I. BASIC script Moving objects between tablespaces in the Oracle database involves multiple types of data objects.Move Table: Alter TableT_aMoveTablespace tbs_a; Mobile index: Alter IndexI _a rebuild

Merge data using relational algebra1Relational algebraThe theoretical basis of Data Set merging is relational algebra, which was proposed by E. F. Codd in 1970.In the formal language of relational algebra:Tables or data sets are used to represent

When writing HQL, subqueries can be used except in the where condition. subquery statements are not allowed in other places, such as select and from. If subqueries are to be written after select, you can use the formula attribute to write data. If

Redis operations on string and hash data Set name xiaohongyang //Get nameSetnx name xiaohyGet nameSetex name 10 jackxiaoSet email xiaohy@yahoo.comGet emailSetrange email 7 qq.comGet emailMset name xhy sex man age 30 // set multiple key values in

CRS cannot be started. Running crsctl start crs has no response View messages:[Root @ UNID02 ~] # Tail-f/var/log/messagesDec 9 08:11:13 UNID02 logger: Cluster Ready Services waiting on dependencies. Diagnostics in/tmp/crsctl.7259.Dec 9 08:12:13 UNID0

Two days ago, the leader gave a live migration to the database. The original system was using the Oracle database and now it was going to be changed to MySql. At that time, I did not think much about it. The original system used the Frame Type SSI,