Rebuild Database

The main content of this paper comes from MongoDB official blog, supplemented by Nosqlfan, this paper analyzes the traditional distributed cache system, and points out that it will bring great pressure to the database in cache reconstruction. and analyzes how MongoDB's mmap scheme avoids this problem. The following diagram of the architecture, in the database front-end with a distributed cache (such as our common memcached), so that the client to access the first lookup Cache,cache not hit the read the database and cache the structure in CAC ...

1.1: Increase the secondary data file from SQL SERVER 2005, the database does not default to generate NDF data files, generally have a main data file (MDF) is enough, but some large databases, because of information, and query frequently, so in order to improve the speed of query, You can store some of the records in a table or some of the tables in a different data file. Because the CPU and memory speed is much larger than the hard disk read and write speed, so you can put different data files on different physical hard drive, so that the execution of the query, ...

No database system can avoid a crash situation, even if you use a clustered, two-machine hot standby ... It is still not possible to completely eradicate the single point of failure in the system, and for most users, this expensive hardware investment cannot be sustained. So, when the system crashes, how to restore the original valuable data becomes an extremely important problem. In the recovery, the ideal situation is that your data files and log files are intact, so that only need to sp_attach_db, the data file attached to the new database, or in the downtime of the ...

Intermediary transaction http://www.aliyun.com/zixun/aggregation/6858.html ">seo diagnose Taobao guest cloud host Technology Hall database system common four kinds of failures are mainly internal fault, system failure, Media failure and computer virus failure, corresponding to each type of failure have different solutions. 　　  A transaction failure indicates that the transaction ended without a commit or revocation, so the database may be in an inaccurate state. ...

No database system can avoid a crash situation, even if you use a clustered, two-machine hot standby ... It is still not possible to completely eradicate the single point of failure in the system, and for most users, this expensive hardware investment cannot be sustained. So, when the system crashes, how to restore the original valuable data becomes an extremely important problem. In the recovery, the ideal situation is that your data files and log files are intact, so only need to sp_attach_db, the data file attached to the new database, or in the downtime ...

This usage is very practical for the following applications: write-intensive cache embedded systems that precede a slow RDBMS system require a lightweight database and a unit test that data in the library can easily be purged without the need for a persistent data-compliant PCI system (testing) If all this could be done, it would be elegant: we would be able to manipulate http://www.aliyun.com/zixun/aggregati without involving disk operations ...

MySQL database sql statement commonly used optimization methods 1. Query optimization, should try to avoid full table scan, should first consider where and order by the columns involved in the establishment of the index. 2. Should be avoided in the where clause on the field null value judgment, otherwise it will cause the engine to abandon the use of indexes and full table scan, such as: select id from t where num is null You can set the default value of num 0, to ensure that Num column table does not null value ...

The intermediary transaction SEO diagnoses Taobao guest Cloud host technology Hall in understanding the Internet entrepreneurship Theory knowledge, began the field to carry out the actual operation of the website business. 　　In this chapter, we will explain in detail how to build a Web site that conforms to the user experience. First, the site's page planning and style design, the choice of the website programming language third, the choice of website database four, the Web site's hardware requirements and preparation of five, server hosting and maintenance six, server performance test seven, domain name query and registration eight, the actual combat exercise ...

ADO. NET is the core of. NET interoperability with the database, and the Ado.net entity database enhances the ability of the. NET application to interconnect with the database, and we can easily strongly type data interoperation with the underlying database through the Ado.net Entity Data model. Greatly facilitates the design personnel, thus also enhances the database operation security. A very special problem has recently been encountered when using the domain data service to siverlight [the results in the application are not the same as the results of the database], after repeated experiments, finally found ...

The complete collection of SQL statement operations deserves to be permanently stored the following statements are part of the MSSQL statement and are not available in Access. SQL classification: ddl-data Definition language (create,alter,drop,declare) dml-Data Manipulation Language (Select,delete,update,insert) dcl-Data Control Language (Grant,revoke, Commit,rollback first, briefly introduce the basic statement: 1, Description: Create number ...