steps to optimize sql query

Label:April 28, 2009Top steps to optimize data access in SQL Server:part I (use indexing)June 01, 2009Top steps to optimize data access in SQL Server:part II (re-factor TSQL and apply best practices)June 08, 2009Top

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

Article 1: how to optimize slow query SQL statements in MySQL56-Introduction to slow logs: in actual log analysis, there are usually a large number of slow logs, at the same time, there will be a large number of records for the same query. here we need to find the most problematic and optimized log in the actual log an

This article describes in detail how to optimize SQL Server database queries. There are many reasons for slow query speed in SQL Server databases. The following are common causes: 1. No index or no index is used (this is the most common problem of slow query and is a defec

Original: Remember the importance of a T-SQL query to optimize indexesOverviewWhen tuning the performance of a project component, it is really important to find the SQL design, so write a blog record to summarize.Environment IntroductionThis project component is a window service that internally uses the round-robin opp

MySQL5.6 how to optimize slow query SQL statements -- Introduction to slow logs Recently, a development team complained that the mysql cluster included in our platform was not good and always reported the "heartbeat Error" of mysql and analyzed the logs they collected, no network problems were found between mysql cluster nodes, but a very interesting phenomenon w

accurate execution plan. Create a statistic for the condition by using the following statement Statistics businesstablefilterstatistics on businesstable (BUSINESSSTATUS1,BUSINESSSTATUS2) where BusinessStatus1= andBusinessStatus2=--withfullscan After the statistics are created, a statistic that you just created is added to the table. Now look at the execution plan for this query, and find that it goes through the index as expected While o

Server is to make sure that the server has enough physical memory.) ）Read-ahead Reads: Like physical Reads, this value does not have any users in query performance tuning. Read-ahead reads represents the physical page that SQL Server reads when it executes a read-ahead mechanism. To optimize its performance, a pre-read data page may or may not be useful, dependi

Recently, a development team complained that the mysqlcluster on our platform was not good and always reported mysql heartbeatError. after analyzing the logs they collected, they did not find any network problems between mysqlcluster nodes, however, I found a very interesting phenomenon. Recently, a development team in mysql's sl complained that the mysql cluster included in our platform was not good and always reported the "heartbeat Error" of mysql. I analyzed the logs they collected and found

SQL data query optimization select nbsp;. id, rkno,. packageno nbsp; as nbsp; packageno, cust_no, lotno, count (*) nbsp; as nbsp; count nbsp; from nbsp; 'rk _ record ' nbsp; as nbsp SQL data query optimization Select. id, rkno,. packageno as packageno, cust_no, lotno, count (*) as count from 'rk _ record 'as a

Steps for Oracle to execute SQL query statements and oraclesql query statements Steps for Oracle to execute SQL query statements If you enter the following

SQL data query optimization select nbsp;. id, rkno,. packageno nbsp; as nbsp; packageno, cust_no, lotno, count (*) nbsp; as nbsp; count nbsp; from nbsp; 'rk _ record ' nbsp; as nbsp; a nbsp; right nbsp; join nbsp;'s SQL data query optimization Select. id, rkno,. packageno as packageno, cust_no, lotno, count

Recently and colleagues to deal with a small program, the data volume is not particularly large, a table of data records: 7000W records around, but from the change to execute a query, but found that the query is not fast, and the most obvious problem is cpu100%.SQL statements:Select from where LNG> and LNG and lat> and LatMax_lat;To find the problem, use the fol

Recently, I have just received a copy of Microsoft SQL Server 2008 English version of the book from the most valuable expert project group-"Inside Microsoft 2008:t-sql Querying" (http:// www.microsoft.com/learning/en/us/book.aspx?ID=12804locale=en-us), roughly turned over and found a lot of changes in content, both new chapters, but also based on SQL Server 2005

Oracle processes query statements in three major stages: parse, execute, and fetch ). Oracle processes query statements in three major stages: parse, execute, and fetch ). Steps for Oracle to execute SQL query statements The query