Database Administrator

Adding virtual memory in linux solves the problem of insufficient swap space Add a SWAP file: 1. view the current virtual memory [Root @ ora11gr2 ~] # Free-mTotal used free shared buffers cached Mem: 2026 217 1809 0 11 126 -/+ Buffers/cache: 78 1947

Blog: http://blog.lingang.me/2014/03/19/redis-find-key-pos/ 1. knowledge required in advance 1. Every database in redis is stored in a redisDb structure. Here, redisDb. id stores the numbers represented by integers in the redis database. RedisDb.

First, I declare that this article is based on the replies from other articles or forums. I extract the key points I think for myself to learn. After all references are attached to the document, we will not thank you here. In the second statement, I

Zookeeper: the connection between the database isolation level and Spring configuration transactions and the impact of performance. The following is my understanding. please correct me if any flaws exist. Take mysql as an example to clarify the

This section describes a special stored procedure, that is, a trigger.I. Concepts of triggersA trigger is a special type of stored procedure, which is different from the stored procedure we described earlier. A trigger is executed when an event is

1. Establish A Logical Data Model as the first stage, including modeling the information that the application needs to process and store, and ensuring that all necessary data can be correctly, completely, and unambiguous. In the implementation of

Dynamic Performance View The data in oracle is changing at runtime. The changed data is stored in the dynamic performance table (memory table, fixed table). It is created as the database starts and increases as the database runs, the dynamic

Author: Liu Xuhui Raymond reprinted. Please indicate the source Email: colorant at 163.com BLOG: http://blog.csdn.net/colorant/ Memcached and Redis are two types of Inmemory key-value databases. They share many similarities in design and ideas.

1. Group function usage rules: In MySql, group functions can be used in select statements at will, but in Oracle, if the query statement contains group functions, If the other column names are processed by group functions or the column in the

I. Database Structure Ii. Oracle Memory Structure 3. Process Structure   1. User process: started when the database user requests to connect to the Oracle server 2. server process: you can connect to an Oracle instance, which starts when a

LEAD and LAG functions in SQL SERVER LEAD and LAG Functions LEAD Access Data in subsequent rows of the same result set, instead of using the self-join in SQL Server 2012. LEAD provides row access based on the given physical offset after the

I haven't written it for a long time. This time I will tell you how to use SQL scripts to automatically add sub-games.Every time a new environment is installed, it is a repetitive task to add a sub-game. How can this problem be automatically

Add the following command to. bashrc under the replicel User: Install a pack rlwrap-0.37-1.el5.i386.rpm [Root @ tyger ~] $ Rpm-ivh rlwrap-0.37-1.el5.i386.rpm Next, modify a parameter: [Oracle @ tyger ~] $ Cat. bashrc#. Bashrc# Source global

Today, a brother told me that SQL runs too slowly. Let me see. The SQL statement is as follows: SELECT rownum row_num, pv.vendor_name, pha.segment1 po_num, prh.preparer_id, pha.Org_Id,

I haven't updated this series of articles for a long time, because of various trivial matters recently. I have not studied for a long time, and it seems that there is only one thing I have learned. I went to the newspaper. Haha, although it is far

Rules for MySQL databases, table names, column names, and aliases in linux: 1. The database name and table name are case sensitive; 2. The table alias is case sensitive; 3. Variable names are case sensitive; 4. The column name and column alias

Set MariaDB auto-start on CentOS Author: chszs, reprinted with note. Blog homepage: http://blog.csdn.net/chszs 1. Check whether MySQL is in the manageable list. [root@Cloud-Q2 ~]# chkconfig --list Abrt-ccpp 0: off1: off2: off3: on4: off5: on6:

1. Step 1: install sqlite command: sudo apt-get install sqlite. If the following information appears after installation, the installation is successful. Reading the package list... completeAnalyzing the dependency tree of the software packageReading

701. A user defined es the following error while loading Ming a large volume of inserts into a table:   The issue is resolved by increasing the space quota on the USERS tablespace for the user. But the user May perform such transaction in the future.

Since the machine has orcale and does not want to install mysql again, there will be a free installation, and it will take a little effort to complete the competition! 1. Download a version without Installation I put in Baidu network disk, here can