how to tune sql query

Tags: style blog http color io ar for strong SPSQL query table, all field names of the table2011-07-29 10:21:43|Category: SQL Server | Tags: table sql fields | Report | Font size Subscription SQL query table, all field names of the tableSQL SERVERView all table nam

T-SQL query advanced-understanding the lock introduction in SQL Server, each query will find the shortest path to achieve their goals. If the database only accepts one connection, only one query is executed at a time. Therefore, queries must be completed quickly and easily.

Introduction In SQL Server, each query finds the shortest path to achieve its goal. If the database only accepts one connection, only one query is executed at a time. Therefore, queries must be completed quickly and easily. However, most databases need to process multiple queries at the same time. These queries will not wait in line like a gentleman, but will be

OK, go to the database log to look for, through the time, keyword batch match. All you can think of is to use it. Let's assume that you've executed it. No? Well, either it's too simple, or you're too easy. Copy Code code as follows: SELECT Top 1000 --Creation time Qs.creation_time, --Query statement SUBSTRING (St.text, (QS.STATEMENT_START_OFFSET/2) +1, (Case Qs.statement_end_offset WHEN-1 THEN datalength (st.text) ELSE qs.

Label: Public classTestsql {@Test Public voidtest01 () {Session session=NULL; Try{Session=hibernateutil.opensession (); List). addentity (Student.class). Setparameter (0, "% hole%"). Setfirstresult (0). Setmaxresults (10). List (); for(Student stu:stus) {System.out.println (Stu.getname ()); } } Catch(Exception e) {e.printstacktrace (); } finally{Hibernateutil.close (session); }} @Test Public voidtest02 () {Session session=NULL; Try{Session=hibernateutil.opensession (); List). Addentity

SQL Server paging query processing method summary, SQL Server Paging Sqlserver2008 does not support the keyword limit, so its paging SQL query statement cannot be performed using MySQL. Fortunately, sqlserver2008 provides top, rownumber, and other keywords, in this way, you

,-1, GETDATE ()),111)//111 is the style number, (100-114)Query first day of the month Date: Select DATEADD (mm, DATEDIFF (mm,0, GETDATE ()),0) asfirstday Query Last day of the month Date: Select DateAdd (MS,-3, DATEADD (mm, DATEDIFF (M,0, GETDATE ()) +1,0)) asLastday//change-The value of 3 changes accordinglyHow many days are there this month:SelectDatePart (Dd,dateadd (dd,-1, DateAdd (MM,1, Cast ((CAST (GE

Tags: type error associated recommendation management will rom Ora no(Transferred from http://blog.csdn.net/sforiz/article/details/5345359) We have to do not only write SQL, but also to write good performance of SQL statements.(1) Select the most efficient table name order (valid only in the rule-based optimizer):The Oracle parser processes the table names in the FROM clause in a right-to-left order, and th

Label:Write in front: This is the first T-SQL query Advanced series article. But the T-SQL query step-up series is far from finished. This topic is advanced and I think it is because this topic requires some advanced knowledge as the basis. If there is any mistake in the article, please do not hesitate to correct me. T

SQL query method essence set, SQL method essence set 1. Simple Query A simple Transact-SQL query only includes the select list, FROM clause, and WHERE clause. They indicate the queried columns, the queried tables or views, and the

Essential SQL query optimization techniques to speed up Website access and SQL access In this article, I will introduce how to identify queries that cause performance problems, how to locate their problems, and how to quickly fix these problems and other methods to speed up the query. You must know that a website with

@ PACK_RECEIVED;Select @ CPU_BUSY;Select @ PACK_SENT;Select @ TIMETICKS;Select @ IDLE;Select @ TOTAL_ERRORS;Select @ IO_BUSY;Select @ TOTAL_READ; -- number of disk readsSelect @ PACKET_ERRORS; -- number of network packet errorsSelect @ TOTAL_WRITE; -- number of disk writes executed by sqlserverSelect patIndex ('% soft %', 'Microsoft SqlServer ');Select patIndex ('soft % ', 'Software SqlServer ');Select patIndex ('% soft', 'sqlserver microsoft ');Select patIndex ('% so_gr %', 'jsonisprogram ');1

19.3.1 SQL Query Analyzer Introduction SQL Query Analyzer is a graphical management tool that is used to write, test Transact-SQL statements, and batch processing. System administrators and developers can learn how to improve performance of

The instance resolution and SQL horizontal display are displayed in the row-to-column manner of SQL query statements. This article shares two examples of horizontal display of rows and columns in SQL query statements for your reference. The specific content is as follows: Ex

1. Use SET STATISTICS TIME ON -- First clear the cache Dbcc dropcleanbuffers; Dbcc freeproccache; -- Run Set statistics time on; SELECT orderid, custid, empid, shipperid, orderdate, filler FROM dbo. Orders WHERE orderdate> = '123' AND orderdate Set statistics time off; GO You will get a similar message: SQL Server Analysis and Compilation Time: CPU time = 15 ms, occupied time = 33 Ms. SQL Server executi

Kettle implements dynamic SQL query and kettle implements dynamic SQLDynamic SQL query in kettle In ETL projects, some SQL statements, such as data query, are usually executed based on the input parameters at run time. This artic

Before: This is the first T-SQL query advanced seriesArticleBut the advanced series of T-SQL query is far from finished. I think this topic needs some advanced knowledge as the foundation. If there are errors in this article, please do not correct it. The content of this article requires the indexing knowledge as the b

Label:ioarjavaforsp Data onbsad Publiclist To get the metadata for the SQL query result set column based on the SQL query

there are usually several ways to tune a database: 1) Manual tuning. The main reliance on people, inefficient, requiring the operator to fully understand the principle of common sense depends on, but also the application, database management system, operating system and hardware have a broad and deep understanding. 2) Case-based tuning . This paper summarizes the recommended configuration val

Tags: velocity hibernateA Brief introductionHibernate provides a more complete encapsulation of the database structure, and Hibernate's O/R mapping implements the mapping between Pojo and database tables, as well as the automatic generation and execution of SQL. While MyBatis is an excellent persistence layer framework that supports plain SQL queries, stored procedures, and advanced mappings, MyBatis needs