Sql Master Database Tables

The logical design of database is a very broad problem. In this paper, the main key design of the table is discussed in the design of MS SQL Server, and the corresponding solutions are given. Primary key design status and problems about database table primary key design, in general, based on business requirements, based on business logic, the formation of primary key. For example, when sales to record sales, generally need two tables, one is the summary description of the sales list, records such as sales number, the total amount of a class of cases, and the other table record of each commodity ...

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 ...

The concept of blockchain to technology has been around for a long time, but with the heat of the past two years, it has gradually become known by the market and many technicians.

Presumably every DBA would like to challenge the data import time, the shorter the work efficiency, the more sufficient to prove their strength. In the actual work sometimes need to import a large amount of data into the database, and then for various program calculation, this article will recommend a challenge 4 seconds limit to let millions data into SQL Server experiment case. This experiment will use the 5 method to complete this process, and detailed records of the various methods of time spent. The tools used are Visual Studio 2008 and SQL Server 2000, SQL S ...

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 ...

In the context of large data, Microsoft does not seem to advertise their large data products or solutions in a high-profile way, as other database vendors do. And in dealing with big data challenges, some internet giants are on the front, like Google and Yahoo, which handle the amount of data per day, a large chunk of which is a document based index file. Of course, it is inaccurate to define large data so that it is not limited to indexes, e-mail messages, documents, Web server logs, social networking information, and all other unstructured databases in the enterprise are part of the larger data ...

Storing them is a good choice when you need to work with a lot of data. An incredible discovery or future prediction will not come from unused data. Big data is a complex monster. Writing complex MapReduce programs in the Java programming language takes a lot of time, good resources and expertise, which is what most businesses don't have. 　　This is why building a database with tools such as Hive on Hadoop can be a powerful solution. Peter J Jamack is a ...

We want to do not only write SQL, but also to do a good performance of the SQL, the following for the author to learn, extract, and summarized part of the information to share with you! (1) Select the most efficient table name order (valid only in the Rule-based optimizer): The ORACLE parser processes the table names in the FROM clause in Right-to-left order, and the last table in the FROM clause (the underlying table driving tables) is processed first, In the case where multiple tables are included in the FROM clause, you must select the table with the least number of records as the underlying table. If...

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 ...

In real life, backing up the database regularly is a very important thing. 　　When we use MySQL, there is a lot of choice in database backup, and this article will show readers how to use MySQL's mysqldump to back up the database. First, the importance of data backup work, if the accidental deletion of important files or directories, then the result will be miserable. Especially when the data that is accidentally deleted involves important customers or key projects, and the data can't be recreated easily, it doesn't have to be what I say you can imagine. Unfortunately ...