sql performance tuning techniques

Program Code Optimization Essentials: String optimization: Parsing string source, understanding string common methods, using StringBuffer, StringBuilder. List, Map, set Optimization: Analysis commonly used ArrayList, LinkedList, HashMap, TreeMap, Linkedhashmap, set interface, set common method optimization. Using the nio:buffered, channel operation and principle, 0 copies are used. Reference optimizations: Strong references, weak references, soft references, virtual referenc

ObjectiveAfter the analysis of the previous few, in fact, in general has been the first glimpse of the importance of SQL Server statistics, so this article will be sacrificed this artifact.This content will be very long, sit good bench, melon seeds snacks and so on ...No nonsense, go to the chase.Technical preparationThe database version is SQL SERVER2008R2, which is analyzed using Microsoft's previous case

configuration. Linux is rich, powerful, and flexible, and you can do a variety of tasks with it, and in this article we'll discuss some tips for improving the performance of Linux servers.1. Tuning the Linux kernel elevator algorithm for disk I/OAfter selecting the file system, there are some kernel and mount options that may affect its performance, one of which

return incorrect results. In the preceding example, if the row exists in DAILY_SALES and the corresponding CUSTOMER key cannot be found in the CUSTOMER table, the rows returned by the preceding query may be incorrect. DB2 Performance Tuning: Using REOPT binding options and input variables in complex queries In an online transaction processing (OLTP) environment, it is critical that the input variable has

executable query statements that are executed at the Master end, and executes the query itself. In this way, the same Query is actually executed on the Master and Slave ends, so the data on both ends is exactly the same.In fact, in the old version, the replication implementation of MySQL was done on the Slave side not by the two threads of the SQL thread and IO thread, but by a single thread to do all the work. But MySQL engineers quickly found that

"Performance Tuning" Oracle AWR reporting metrics full resolution What is AWR? ===================================================================================================== AWR (Automatic workload Repository) A bunch of historical energy data, placed on the Sysaux table space, AWR and Sysaux are all 10g, are the key features of Oracle tuning; About

Io is very relevant, when the free buffer waiting in the v$session_wait of the entry is very small or not, Explain the DBWR process of your system will be enough, do not need to adjust, there are many items of free buffer wait, your system must feel very slow, then your DBWR is not enough, the resulting wio has become your database performance bottlenecks, the solution is as follows: A.1 to increase the write process while adjusting the db_block_lru_

gp4.1 and previous SQL with not in will be executed with Cartesian product, using nested join, very poor efficiency Not in== use the left join to go back to the table Association to implement Example select * from test1 where col1 not in (select col2 from test1)Switch select * from test1 a left join (select col2 from test1 group bycol2) b on a.col1=b.col2 where b.col2 is nullThe run time is increased from more than 30 seconds

Label:MySQL performance tuning and architecture design--1th chapter MySQL Basic introductionPreface:As one of the most popular open source database software, MySQL database software has been widely known. But in order to take care of the readers who are not familiar with MySQL, this chapter will make a brief introduction to MySQL. The main content includes MySQL each function module composition, each module

which some statements in SQL Server take advantage of the index may not be clear, our next analysis of this piece, to understand the indexing method and optimization techniques, interested in advance attention, about SQL Server performance tuning involves a wide range of co

the deterioration of performance is a variety of factors, and sometimes the results of the performance degradation caused by multiple elements, this requires the database administrator has a more comprehensive computer knowledge, can be sensitive to the impact of the database performance of the main reason. In addition, good database management tools are also im

2009 21:00 1 7472 25 October 2009 22:00 1 7473 25 October 2009 23:00 1 7474 26 October 2009 00:00 1 7475 26 October 2009 01:00 1 7476 26 October 2009 02:00 1 7477 26 October 2009 03:00 1 7478 26 October 2009 04:00 1 7479 26 October 2009 05:00 1 7480 26 October 2009 06:00 1 7481 26 October 2009 07:00 1 7482 26 October 2009 08:00 1 7483 26 October 2009 09:00 1 7484 26 October 2009 10:00 1 Specify the Begin and End Snapshot Ids ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Enter value for begin_snap:7451

Program | index | performance You can use SQL Server adjuster (SQL Server Profiler) tools to collect important information about the current activity of the server. The information tracked by this profiler tool, which contains the real load of the database, can be used on a variety of occasions. Now let's look at how to use Profiler to collect the data that can b

Summary: This article begins with a detailed introduction to the concept of shared pool in Oracle and the memory structure included. It then provides an in-depth overview of Oracle's management mechanisms for shared pool. Finally, the paper introduces the practical method of buffer cache monitoring and tuning. 1. The concept of shared pool Oracle databases, as a product of managing data, must be able to recognize the administrative commands (often c

Source Address: https://msandbu.wordpress.com/2014/10/31/netscaler-and-real-performance-tuning/The author is obviously not a native English speaker, so some places I look at is also more laborious, but very grateful to the original author.========= translated content started =========Yesterday I had a meeting with Citrix User group in Norway on NetScaler and performance