Database Administrator

1. database data volume surge. Compared with databases similar to other services, the data volume of a table is abnormal. Finally, a bug of repeated data migration is identified... 120301 17:30:43 [ERROR] Column count of mysql. db is wrong.

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

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 --

Recently, a field-based query function is provided for each table in our system. The foreground sends json data to the backend, And the backend performs Fuzzy Matching by %, query by field. the result is rejected. another colleague used Hibernate

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

Replace into is very similar to insert into. The only difference is that when replace into is used, the system first checks whether there is a record that is the same as the statement to replace into Based on the table's primary key, if yes, delete

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

PL/SQL contains two types of cursors: 1. Display cursors 2. Implicit cursors Display cursor:Syntax:CUROSR cursor_name is select_statement;Open cursor: open cursor_name;Extract data: 1. FETCH curosr_name INTO varible1, variable2 ....;2. FETCH

Replace variables (only used for SQL * Plus or development tools with the same principle as SQL * Plus ):Temporary storage valueIt can be used to create a general script.It can be used to interact with users, so it is also called interactive

(1) Requirements for installing mysql5.5 The compilation and installation of mysql5.5 is a little different from that of 5.1, because mysql uses cmake as the compilation Engineering tool. This is the biggest difference from mysql5.1, so the Toolkit

View table space and Data File InformationSelect tablespace_name, file_name, ceil (bytes/1024/1024) mbFrom dba_data_files order by 1; Create a tablespace Create tablespace tanzugan logging datafile 'H: \ APP \ ZUGANTAN \ ORADATA \ ORCL2012 \

Allows users to partition data that does not have a logical rangeYou can run the HASH function on the partition key to determine the partition to store.Evenly distribute data to different partitionsSyntax: PARTITIONBYHASH (column_name) PARTITIONS

In versions earlier than Ubuntu 12.04, It is very convenient to configure the MySQL database. You only need to run three commands: Sudo apt-get install mysql-server Sudo apt-get install mysql-admin Sudo apt-get install mysql-query-browser Ubuntu

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

Starting from Oracle9i, Oracle provides a Web-based sqlplus interface. With iSQL * Plus, you do not need to install any Oracle client, you can use sqlplus in the browser to perform data operations and database management. Generally, you can log on

Oracle multi-field max/min Function We know that max or min is used for finding the maximum and minimum values in a column; You can use greatest and least to calculate the maximum and minimum values for multiple columns and fields (not sure the

MHA is divided into management nodes and database nodes. database nodes are composed of mysql master-slave or master-slave nodes. When the master database fails, the management node will automatically upgrade from the master node to the master node;

ROWID determines Based on the index:SQL> select rowid from; ROWID ------------------ AAAQ/LAACAAABacAAA AAAQ/LAACAAABacAAB SQL> desc; Name Null? Type ----------------------------------------------------------------------------- Id not null number (5)

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

When modifying the Oracle data field type, you can change the data in the table as follows: Alter table name rename column field name TO field name 1; Alter table name ADD field name VARCHAR2 (30 ); UPDATE table name SET field name = CAST (field