sql server 2014 slow performance

predict the size of the real data, that is, the first step is wrong, resulting in each step behind the first step of interference, often followed by loop join execution, this way for a smaller result set, of course, no problem, If you encounter a large result set, it is very inefficient (see a lot of super-complex, join tables, very complex query conditions, and the slow-running Sql,

actual index used. If NULL, the index is not used. Key_len: The length of the index used. The shorter the length the better, without loss of accuracy Ref: Shows which column of the index is being used and, if possible, a constant Rows:mysql the number of rows that must be checked to return the requested data Extra: The return value to note (extended column) Using Filesort: When you see this, the query needs to be optimized. MySQL requires additional steps to find out how to sort the rows that a

Uncover new features of SQL Server 2014 (1)-memory database, sql2014 Introduction SQL Server 2014 provides many exciting new features, but one of the most anticipated features is the memory database. When I attended the opening ce

The traditional relational database service engine is often not the best platform for analyzing and computing ultra-large amounts of data, so SQL Server has developed an analytics service engine to analyze and calculate large amounts of data. Of course, for the data storage platform SQL Server database engine, there is

With regard to the use of SQL Server Profiler, there are already many tutorials on the web, such as this article: SQL Server Profiler: How to use and metrics. Microsoft Official Documentation: https://msdn.microsoft.com/zh-cn/library/ms179428 (v=sql.105). aspx is described i

, the performance may be faulty. Column storage indexes only support Scan operations, as shown in figure 1. Figure 1. Column store indexes only support Scan operations How is column indexes stored? Column index storage is simply stored by column. This process can be divided into three stages: first grouping a bunch of rows, this is the so-called "Row group". After grouping is complete, sharding by column, and finally compressing the column, 2. Figur

Comparison of several scenarios for high availability in SQL Server 2012, where AlwaysOn advantage is compared to several scenarios for SQL Server 2012 high availability and disaster recovery, replication, clustering, mirroring, what are the advantages of new technology AlwaysOn,This article will make a rough compariso

Label:For SQL Server databases, performance has been a topic that is not always around. And when we analyze and study performance issues, the execution plan is one of the priorities we've been focusing on. We know that at compile time, SQL

SQL Server 2014 CTP2 publishes a feature for backup, which is native backup encryption. In view of the previously bad impact on the network database leakage events, is essentially a database backup leaked to the third party, SQL Server's original data backup can make even if the backup itself is stolen, without the enc

This is my manuscripts in IT168, the original address: http://tech.it168.com/a2014/0620/1637/000001637358_all.shtml The IT industry has entered the cloud era, and more and more enterprise IT infrastructures will be deployed in public, private, or hybrid clouds, and the database as the most important part of the IT infrastructure and the cloud will become very important. SQL Server

cases, the optimizer reliably selects the most efficient index. All policies should provide good index optimization options. I believe this is the correct decision. This can reduce the analysis time and provide good performance in multiple situations. Next we will introduce the index. Check the WHERE clause of SQL queries because it is the main focus of optimization. The columns listed in the WHERE claus

average IOPS in a particular resource pool. In addition, Disk Write IO throttled/sec performance counters will also tell you the number of IOPS for your resource governor. Using the previous resource Governor, the query itself was helpless and whether it was suppressed. This is also a very important factor for performance tuning. When resource Governor is enabled, no specific wait type appears in

The IT industry is already in the cloud, and more and more enterprise IT infrastructures will be deployed in public, private, or mixed clouds, and it will be important for the database to be the most important part of the IT infrastructure to be integrated into the cloud. SQL Server 2014 opens up the relationship between the public cloud and the organization, whe

Yesterday's SQL Server query performance optimization-index creation principle (I) mainly introduced the principle. today are some of the main principles and checks the created indexes. Iii. indexing principles In general, building indexes depends on the data usage scenarios. In other words, which SQL statements are co

SQL Server 2014 installation Diagram SQL Server 2014 Enterprise Edition, business intelligence edition, and Standard Edition support the following operating systems: Windows Server 2008

, as shown in Figure 4. Figure 4. Creating a Memory tuning table Currently SSMS does not support creating a memory tuning table for the UI interface, so you can only create the memory tuning table through T-SQL, as shown in Figure 5. Figure 5. Creating a Memory tuning table using code Once the table is created, you can query the data, and it is worth noting that the query Memory tuning table requires snapshot isolation levels or hint, which is