identify poor performance in sql server

There are already many paging query methods, and I am also a member here. SQL Server has a set rowcount setting, which means that the command processing stops processing the command after responding to the specified number of rows, we can use it to implement high-performance paging query in a 10 million row-level data table. Let's talk about the implementation me

Paging query has a lot of ways, and here I also join as a member. SQL Server has a SET ROWCOUNT setting that means that the processing of a command stops processing the command after responding to a specified number of rows, and this feature allows us to use it to implement a high-performance paging query in a tens of millions of row-level datasheets. First of al

(@pagesize) * FROM (select Top (@page * @pagesize) * createtime desc) liwu_items ORDER BY createtime ASC) b ORDER BY createtime Desc Results (12 rows affected) Table ' Liwu_items '. Scan count 1, logical read 7 times, physical read 0 times, read 317 times, LOB logic read 0 times, lob physical read 0 times, lob read 0 times. Execution plan The execution plan is similar to the first, but two of the resources are quite a bit. The third, one of the most rubbish, is implemented

There should be different filegroups in the database before the partition table is created;Assuming the database name is Df17datapro, create the user table UserID, put the first 500,000 data in the primary filegroup, place the 50~100 in the FG1 filegroup, and put more than 100 in the FG2 filegroup1. Add File group Fg1,fg2ALTER DATABASE Df17datapro ADD FILEGROUP FG1ALTER DATABASE df17dataproadd FILEGROUP fg22. Adding files to a filegroupALTER TABLEDf17dataproADD FILE(NAME=Df17datapro1,filename=

One, include for nonclustered indexesThe Include property of a nonclustered index allows a nonclustered index to contain additional columns. Such asCREATE nonclustered INDEX [nonixuser] on [dbo]. [Users]([NAME] Asc)INCLUDE ([ID], [creattime]) GOThis table statement adds the ID on the nonclustered index of the name column, and the Createtime column.In the previous introduction, we know that when querying name = ' 3,180 ', the RIDs will appear, while the number of reads is 3 timesNow add the Inclu

number of rows on the page.How is the analysis performed? The reference document says:For example, the second row of 0x 4f000000 0100 1200 minus the beginning of the 16 binary, the total 8 bytes left, from the right to the left row 2 bytes, the file ID2 bytes, the leftmost 4 bytes is the page number, soLine number (0012) =18File pages (0001) =1Page number (0000004F) = 59 pageIn summary, the 202 page is the root page of the nonclustered index, and the second line is "3,179", which points to a su

databases after a large number of updates. The system databases that must be backed up includemsdb、MasterAndModel。 If you have any databases that use replication on the server instance, you must also back upDistributionSystem database. By backing up these system databases, you can restore and restore the SQL Server system in the event of a system failure, such a

There are four variables that affect the performance of tape backup devices and allow SQL Server backup and restore performance operations to increase the linear proportions of the system by substantially adding more tape devices. Software data block size Number of tape devices sharing a small computer system interfa

parameterization.Sqlserver:sqlstatistics/failed auto-params/secNumber of failed automatic parameterization attempts per second. the value should be very small. Note that in later versions of SQL Server, automatic parameterization is also known as simple parameterization.Sqlserver:sqlStatistics/batch requests/secNumber of Transact- SQL command batches received pe

(user_lookups), if these two values are small, you might consider dropping the index.When you restart the SQL Server service, the various counters in the Sys.dm_db_index_usage_stats system view are initialized to null values. In addition, whenever data is detached or closed (for example, because Auto_Close is set to ON), all data rows associated with the database are deleted. When an index is first used, i

jobsWhere exists (select 1 from employee where job_id = jobs. job_id) AsProgramNote:1. Pay attention to the data volume of each table.2. Try to test the Encoding Process and unit test process in a database with a large amount of data. It is best to test the actual data.3. Every SQL statement should be as simple as possible4. Do not update the data of tables with triggers frequently.5. Pay attention to the limitations of database functions and their

SQL Server database Performance optimization SQL statement text address: http://www.blogjava.net/allen-zhe/archive/2010/07/23/326927.htmlPeriod project needs, did a period of time the SQL Server

InSQLServer, the view is a stored T-SQLQuery. View DefinitionSQLServer saves, so that it can be used as a virtual table to simplify queries, and adds another layer of security to the base table. However, it does not occupy any space in the database. In fact, the view does not do anything before you query it. Index View InSQLIn Server 2000 and 2005, you can add indexes to the view. However, if the view is just a query definition stored in the database

to archive, partition, table sharding, etc) Software System (operating system optimization, database system configuration, resource planning and monitoring, etc) Hardware infrastructure (Device specifications, hardware performance, Server Load balancer, Disaster Tolerance, etc) SQL statement writing, indexing and statistics, transactions and locks, application a

SQL Server database performance optimization http://www.blogjava.net/allen-zhe/archive/2010/07/23/326927.htmlRecent project needs, did a period of time SQL Server performance optimization, encountered some problems, but also accum

tools such as Sqlio.5. Always place the log file on the RAID10/RAID1.6. Isolate the log files and data files from the physical disk.7. Carefully consider the data configuration of tempdb.8. Balance the number of data files with the capacity of the CPU.9. Do not neglect the foundation of SQL Server.10. Do not neglect the storage configurationMonitoring of SQL