Shulou(Shulou.com)05/31 Report--

In this issue, the editor will bring you about the factors that affect the speed of SQLServer database access. The article is rich in content and analyzes and describes for you from a professional point of view. I hope you can get something after reading this article.

What are the factors that affect the speed of SQLServer database access

Factors affecting performance

There are several common factors that affect the speed of data access:

1. No index or no index database index is like a catalog in a book, so that when users access database data, they can find the data they need without traversing all the data. After creating the index, we can ensure the uniqueness of each row of data and greatly improve the efficiency of data retrieval, which is a way to sacrifice space for performance. Not having an index or not using an index is the most common cause of slow data access, and it is also a flaw in programming.

The small throughput of 2.I/O results in the bottleneck effect. The throughput is the objective factor (hardware factor) that affects the data access speed. In a certain hardware environment, the optimized deployment scheme can appropriately improve the throughput of Icano.

3. Does not create the computed column causes the query not to optimize the computed column is a special column, do not fill in any design type, the user can not change the value of the column. The value of a calculated column is the result calculated by a certain function formula and so on, taking the value of another or more columns as input values. If there is no corresponding calculation column, it is necessary to calculate the existing data when querying some data, thus wasting some performance.

4. There is no doubt that the query access to database data with insufficient memory will occupy a lot of memory space. when there is insufficient memory, the data access speed will be significantly affected or even timeout, which is the objective factor affecting the data access speed.

5. The slow speed of network is the objective factor that affects the speed of data access. It can be solved by increasing the bit width of network access.

6. The amount of data queried is too large when the amount of data queried is too large, the occupation of memory and system time all affect the speed of data access. Multiple queries, location queries, and query data volume control can be used to solve the problem.

7. Lock or deadlock or deadlock will cause the visitor to wait for the time process or never get the resource when accessing the database data. This is one of the most common causes of slow query, and it is a defect in programming, which should be avoided as far as possible.

8. Return unnecessary rows and columns in the general data query, all get as much data information as possible, which results in unnecessary data traversal and greatly increases the response time of data access. Therefore, in the general query, we should query as few rows and columns as possible to minimize the data traversal time to meet the data output requirements.

9. Query statement is not optimized enough in the process of data query access, the most frequently used is the use of custom query statements for data output. Therefore, writing optimized query statements can greatly improve the speed of data query access.

Performance optimization database performance optimization is mainly to improve the speed of data access, that is, to improve the performance index of database response speed. Performance optimization is mainly divided into two parts: subjective factors and objective factors. Here, we mainly optimize the objective factors that affect the performance.

What are the factors that affect the speed of SQLServer database access

Optimization of subjective factors

Subjective factors mainly refer to the hardware environment of the server. The main optimization has the following aspects:

1. Put the data, logs and indexes on different Imax O devices to increase the reading speed. The larger the amount of data is, the more important it is to improve the throughput of Imax O.

2. Divide the table vertically and horizontally to reduce the size of the table (sp_spaceuse)

3. Upgrade hardware

4. Improve the speed of network access

5. Expand the memory of the server; configure virtual memory: the virtual memory size should be configured based on the services running concurrently on the computer, generally set to 1.5 times the physical memory; if the full-text search function is installed and you plan to run the Microsoft search service to perform full-text indexing and queries, consider setting the virtual memory size to at least 3 times the physical memory in the computer

6. Increase the number of server CPU, in which parallel processing needs more resources than serial processing. SQLSERVER determines the optimal level of parallelism according to the system load. Complex queries that consume a lot of CPU are suitable for parallel processing. However, update operations such as UPDATE, INSERT and DELETE cannot be processed in parallel.

These are the factors that affect the access speed of SQLServer database. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.