how to identify poor performance in sql server

A common performance counter for SQL Server servers, in this flag. Performance object Counter Description Processor %processor time%privileged time Recommended value: lasts less than 80Recommended value: lasts less than 10 System Processor Queue Length

= 'white'Indexes created on the following columns will be useful to the optimizer.Au_lnameAu_lname, au_fnameThe indexes created in the following columns will not play a good role in the optimizer.Au_addressAu_fname, au_lnameConsider using narrow indexes on one or two columns. Narrow indexes are more effective than multi-index and composite indexes. Use a narrow index on each pageThere will be more rows and fewer index levels (relative to Multiple indexes and composite indexes), which will promo

SQL Server query performance optimization analysis transactions and locks (2 ). Step 1: Execute Example 2 and Example 3 code in the query analyzer. (This is the example in the previous article SQLSERVER query performance optimization analysis transactions and locks (2) -- Example 2 6 is locked by 53

SQL Server query performance optimization analysis transactions and locks (I) SQL Server query performance optimization analysis transactions and locks (ii) SQL

SQL Server query performance optimization and analysis of transactions and locks (1) Step 2: analyze the locking status using SQL statements. sys. in the sysprocesses view, find out the source of waiting for the initial lock of resources and the subsequent processes to be forced to stop. The following code is applicabl

In SQL Server database operations, we often use stored procedures to implement the query data paging to facilitate the browsing of the viewer. In this article, we summarize the methods of five SQL Server paging stored procedures and compare their performance, so let's take a

consuming a lot of CPU usage (for example '%Hash Match%’、‘%Sort%') to identify suspicious objects. Select * fromSys.dm_exec_cached_plans Crossapply Sys.dm_exec_query_plan (plan_handle)wherecast(Query_plan as nvarchar(Max)) like '%sort%'or cast(Query_plan as nvarchar(Max)) like '%hash match%' 9, if you have detected a query plan that is inefficient and that causes high CPU usage, run the tables that are involved in the queryUPDATE STATISTICSTo see if

SQL Server Performance Tuning 3 Index MaintenancePreface The previous article introduced how to improve database query performance by creating indexes, which is just the beginning. If you do not need proper maintenance in the future, the indexes you have previously created may even become a drag-and-drop attack and a h

Label:Source code files 1, what is a performance issue? If the existing resources do not reach the maximum throughput, the system cannot meet the reasonable expected performance, then it can be defined as a performance problem. Performance metrics include: response time, throughput, scalability. 2, a preliminary stud

execution. Then, there are operators that require additional memory space to store row data, and the amount of memory required by such operators is usually proportional to the number of rows of data processed. This can cause memory to not be applied if any of the following conditions affect execution performance A, if the server is performing other similar memory consumption of large queries, resulting in

N a long time ago, I read the technical insider's section on CPU analysis. I wrote one article, but before I finish writing it, I have something to do. Later I thought I had published it. I saw it in the draft box today. I sorted it out and published it... The Analysis of CPU utilization focuses on CPU bottlenecks, compilation, and decompilation. 1. CPU bottleneck You can check the Processor: % Processor Time counter in PERFMON to determine whether there is a hard bottleneck. If the value 1 is t

change the original table to the online table has been modified failed. After you temporarily disable SQL Server account, you can modify the name of the table.Analysis: There is a schema-stable lock during SQL execution, and it is easy to modify the data structure failure for highly concurrent access tables. It is recommended that you temporarily stop the busine

SQL Server performance analysis query table space and available space Posted @ zping read (58) | comment (0) Edit Interval between querying long transactions and SQL Execution Posted @ zping read (110) | comment (0) Edit Query execution information of SQL

milliseconds) above and the maximum wait time as a reference. Using the information provided by Sys.sysprocesses to count, about sys.sysprocesses use can refer to "SQL Server performance tuning from user session state analysis". This view listens for blocking information over a period of time. You can set a monitor statement to run every 10 seconds, storing bloc

SQL Server performance optimization involves many aspects, such as good system and database design, high-quality SQL writing, appropriate data table index design, and even various hardware factors: network performance, server

The SQL Server compact product group published a blog article about how to improve the query performance of the SQL Server compact database. It is comprehensive and authoritative. We suggest you take a look. In fact, the SQL

Recently due to work needs, I hope that a more comprehensive summary of SQL Server database performance optimization related considerations, search on the internet, found a lot of articles, and some are listed hundreds, but look at the discovery, there are many specious or outdated (may be on the SQL SERVER6.5 the prev

performance gains of indexes, it's very difficult to actually build enough correct and necessary indexes at the outset, how can we infer which tables need to be indexed and which ones are not built correctly?Typically, SQL Server executes a query script with an existing index, assuming that no index is found he will voluntarily generate one and store it in the D

Tags: analyze one moni min sim data soft databases ImpConnection poolhttps://www.mssqltips.com/sqlservertip/5630/understanding-sql-server-connection-pooling-in-adonet/Open Activity Monitorhttps://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/ open-activity-monitor-

Because the company's project encountered database operation performance problems after going online and running, it needs not to be changedCodeIn this case, the database performance is optimized, so I found the relevant information and wrote down my experience.1. most database performance bottlenecks are concentrated on query statements. for