Sql Server Primary Key Clustered

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 ...

Designing 1 applications doesn't seem to be difficult, but it's not easy to achieve the optimal performance of the system. There are many choices in development tools, database design, application structure, query design, interface selection, and so on, depending on the specific application requirements and the skills of the development team. This article takes SQL Server as an example, discusses the application performance optimization techniques from the perspective of the background database, and gives some useful suggestions. 1 database design to achieve optimal performance in a good SQL Server scenario, the key is to have 1 ...

Setting filter conditions to improve indexing efficiency good indexes are key to SQL Server database performance, but efficient indexes are carefully designed. As we all know, a primary key is a unique identifier for a data object, and if there is no clustered index in the datasheet, the SQL Server database will create a clustered index (Clustered index) for the primary key by default in order to maintain the uniqueness of the key. Unless the user specifically specifies that the index should be created as a nonclustered index (non-clustered index). There is no doubt that we ...

The concatenation (join) and segmentation (split) of MSSQL strings are often used by masters using select number from Master. spt_values WHERE type = ' P ', this is a good way to do it, but there are only 2048 digits, and the statement is too long and not convenient. In short, a digital assistance table (100,000 or 1 million per person needs), you deserve it. 2. Useful index of the calendar table: ★★★☆☆ "SQL Programming Style" a book suggests an enterprise ...

A good database product is not equal to have a good application system, if can not design a reasonable database model, not only will increase the client and Server section program programming and maintenance of the difficulty, and will affect the actual performance of the system. Generally speaking, in an MIS system analysis, design, test and trial run stage, because the data quantity is small, designers and testers often only notice the realization of the function, but it is difficult to notice the weak performance, until the system put into actual operation for some time, only to find that the performance of the system is decreasing, At this point to consider improving the performance of the system will cost more ...

In large data technology, Apache Hadoop and MapReduce are the most user-focused. But it's not easy to manage a Hadoop Distributed file system, or to write MapReduce tasks in Java. 　　 　　Then Apache hive may help you solve the problem. The Hive Data Warehouse tool is also a project of the Apache Foundation, one of the key components of the Hadoop ecosystem, which provides contextual query statements, i.e. hive queries ...

The hardware environment usually uses a blade server based on Intel or AMD CPUs to build a cluster system. To reduce costs, outdated hardware that has been discontinued is used. Node has local memory and hard disk, connected through high-speed switches (usually Gigabit switches), if the cluster nodes are many, you can also use the hierarchical exchange. The nodes in the cluster are peer-to-peer (all resources can be reduced to the same configuration), but this is not necessary. Operating system Linux or windows system configuration HPCC cluster with two configurations: ...