Database Administrator

Recently, many features have been developed, and I feel quite familiar with the English name for many programming processes. However, to view the functions, I need to open comments or code at each point. I feel very depressed. We can see packages

1. Transaction concept: Concept: transactions in databases are logical units of work. A transaction is composed of one or more SQL statements that complete a group of related behaviors, the transaction mechanism is used to ensure that the operations

Pymongo is a high-performance, file-based database written in Python.Download and install.[Monogdb @ localhost bin] $ wget http://pypi.python.org/packages/source/p/pymongo/pymongo-1.9.tar.gz#md5=12e12163e6cc22993808900fb9629252-- 21:21:18 --

First, use Oracle-xe to create a database (use root ).Rpm-ivh oracle-xe-univ-10.2.0.1-1.0.i386.rpmOracle. dba is created.Basic Configuration:/Etc/init. d/oracle-xe configure In this case, You Can su-oracleConfigure environment variables.Focus on

Condition branch statement•IF statement:-IF-THEN-END IF-IF-THEN-ELSE-END IF-IF-THEN-ELSIF-END IF-Case statement:• Cyclic statements-LoopSyntax: IF condition THEN Statements; [ELSIF condition THEN statements;] [ELSE statements;] End if;

When the LV status is abnormal during the database management process and the LV cannot be used again, what are the two LV statuses in AIX? If open is required to access fs, that is, to create a file system and mount the file system lv state, it is

When I first came into contact with PHP and started to contact MYSQL, many people said: "MySQL is enough to run on a small site with hundreds of thousands of IP addresses a day. If it is a few millions of IP addresses, it won't work ", I don't

For work, you need to write a method or SQL statement to retain the decimal point. For decimal places of the number type, if it is 0.5 or-0.5, it will be displayed during printing. 5 or -. 5. Obviously it's not what I want. I wrote a simple one

Recently, I have been playing with DG. Due to the shortage of disk resources, a policy for archiving logs is required. I found several scripts on the Internet and found that writing is so troublesome. Mao, So I simply wrote one, and the actual path

Problems with Oracle DG archive setup Verification -- Master database SQL> col statusForA10 SQL> col destinationForA20 SQL> col errorForA20 SQL>SELECTSTATUS, DESTINATION, ERRORFROMV $ ARCHIVE_DEST; STATUS DESTINATION ERROR -----------------

When I was writing JDBC, I met the problem that the SQL statement cannot run because it contains Chinese characters. So I put this sentence in the mysql client for testing and the result passes, I guess it's not a matter of character encoding. It's

I used Ubuntu 10.04 LTS Server. The HDD was faulty a few days ago and the system was pregnant. I had to wait for an 80 GB HDD to be eliminated with IT. How can the company be so poor, I still use my computer as the server 7 or 8 years ago. Is IT

Statement for inserting database data:Insert into testtab (FIELD1) VALUES ('test ')If the string to be inserted to the database contains single quotation marks, escape is required. For example, to insert "It's a tree.", the SQL statement is as

The Like operators in Oracle use '_' and '%' As wildcards, just Like this: SELECT name FROM test_like WHERE name like'_ A %'; That is, all rows with the 2nd letters a in the name column of the test_like table are matched. However, note that Oracle

Recursion in Oracle: Table structure similar to tree structure:Id name parentId1 a 02 A-1 13 B 04 a-1-1 2B-1 36 a-1-2 2A-2 1 78 a-2-1 7 SELECT * FROM table name start with id = 'Connection by prior id = parentId; Start ...... In the usage of connect

Create undo tablespace MOZI datafile 'e: \ Oracle \ product \ 10.2.0 \ oradata \ orcl \ MOZI. dbf' size 2048 M extent management local;Alter system set undo_tablespace = MOZI;The ORCL database in WINDOW prompts: the database is not open: it can only

1. Command installation: yum install mysql-server 2. built-in startup: CentOS6.2 comes with mysql5.1 installed, and the root identity (mysql-u root-p) has no password; System-> Management-> service, select mysqld, and set auto start and start the

-- Log on to Oracle Sqlplus/as sysdba -- Query lock Information Select t2.username, t2.sid, t2.serial # from v $ locked_object t1, v $ session t2 where t1.session _ id = t2.sid and rownum Result: Username sid serial #---------------------------

In the basic configuration information table of the application, some dictionary information is saved. The key value is added by the application in sequence as needed. This type of requirement is used for primary key field value management. The

Recently I am studying Oracle 10G. Let's start with the installation. During the installation, the default port 1521 is occupied by other programs. After installing oracle, the port is changed to 1522. 1. So I changed the port to 1521 again. At that