Database Administrator

I. Database Design ProcessDatabase technology is the most effective means of information resource management. Database Design refers to constructing the optimal database mode for a given application environment, establishing a database and its

In the design of dynamic websites, the importance of database design is self-evident. If the design is not proper, the query will be very difficult and the program performance will be affected. Whether you are using a mySQL or Oracle database,

Select *From openrowset ('Microsoft. Jet. OLEDB.4.0', 'Excel 8.0; HDR = YES; IMEX = 1; DATABASE = d: \ folder \ excel.xls ', Sheet1 $)------- NOTE ------Setting IMEX = 1 tells the driver to use Import mode. in this state, the registry setting

Here is an example of SQL server2005:Create table tb (province nvarchar (10), city nvarchar (10), score int)INSERT tb SELECT 'shaanxi ', 'xiance', 3Union all select 'shaanxi ', 'ankang', 4Union all select 'shaanxi ', 'hanzhong', 2Union all select

Let's give a general explanation.Example TableAid adate1 a12 a23 a3Table BBid bdate1 b12 b24 b4Two tables a and B are connected. fields with the same id must be retrieved.Select * from a inner join B on a. aid = B. bid this is only used to retrieve

Summary:1. Stored Procedure: For SQL statement batch processing, common continuous operations are made into batch processing in the form of application and service.Solve the bottleneck: a large number of SQL queries are slow s2. Index Service:

The flashback query is introduced in oracle 9i. The flashback query actually uses the UNDO information to obtain the previous data. Since the UNDO space is used cyclically and the pre-transaction image cannot be permanently saved, the flashback

As we all know, zabbix's custom key function is very convenient and it is very convenient to monitor any value. After the installation, if you need to monitor mysql, you cannot use the default template, because no key exists, you need to write a

Pub/sub is a message communication mode. The main purpose is to decoupleCoupling, which is similar to the observer pattern in the design pattern. Pub/sub not only solves the Direct Problem of publishers and subscribersCode-level coupling also solves

For more blog posts, please note: Children without umbrellas must keep running.(Www.xuchanggang.cn) In the previous article, we used mysql-mmm to dynamically monitor the mysql database. This article uses amoeba to implement read/write splitting for

Environment Introduction: Dual-host operating system: solaris 10 database version: oracle 11g R1 64bit 1. I received a call in the middle of the night, saying that the database reported a large number of errors. I checked the database and found the

The archive mode switching in the RAC environment is slightly different from that in a single instance, mainly because of the differences in shared storage. In this case, we can switch the RAC database to a non-cluster state and switch the archive

Change the system session mode to disenable restricted to create conditions for the initiation of snp. Alter system disenable restricted session; Job_queue_processes = 10 (oracle10gde default value)Job_queue_interval = N Alter system set job_queue_

1. We will first add the Union unique index, which is generally to remove other fields after the id field ALTER ignore TABLE 'test' ADD unique INDEX ('Loan _ account', 'num', 'name', 'monney _ start', 'monney _ yue ', 'date ', 'end', 'lil', 'jiaoyi

The difference between a RAC database and a single instance is that multiple instances manage shared resources in a unified manner through cluster components. Therefore, you can use the original management methods for a single instance, such as

In some specific circumstances, sometimes you need to connect to the specified instance in RAC from the client, instead of dynamically selecting the client Load_balance or forwarding the server listener Based on the load situation. In this case, you

1. Disable all constraints in the database first.Select 'alter table' | table_name | 'Disable constraint' |Constraint_name | ';'From user_constraintsWhere constraint_type = 'R ';Run the command to disable all constraints.2. delete data from all

Note: note the conditions when performing the update operation. If the where clause is left blank, the full table is updated. If the table is not updated, null values are assigned. Update a single table: update tablename set col1 = value where col2

Http://boylook.itpub.net/post/43144/520543 The biggest feature of MV data migration is its flexibility, which enables cross-platform and cross-database version migration and data restructuring and optimization. The implementation principle of this

MySQL Performance murder -- SWAP Story: Recently, the company launched a new project about searching for a project. Its program will call a large number of SQL statements, including searching for various conditions, Fuzzy Matching, association