oracle performance tuning tips

be reported as ' too many connections ' error. For the value setting of wait_timeout, it should be judged according to the operation condition of the system.# After the system has been running for a period of time, you can view the current system's connection status through the show Processlist command, if you find a large number of sleep status of the connection process, the parameter setting is too large,# you can make the appropriate adjustments smaller. To set Interactive_timeout and wait_t

value setting of wait_timeout, it should be judged according to the operation condition of the system.# After the system has been running for a period of time, you can view the current system's connection status through the show Processlist command, if you find a large number of sleep status of the connection process, the parameter setting is too large,# you can make the appropriate adjustments smaller. To set Interactive_timeout and wait_timeout at the same time will not take effect.[Mysqldump

more information: Open source distributed database middleware mycat:http://blog.oldboyedu.com/mysql-mycat/Mycat: Open Source distributed database middleware: http://www.csdn.net/article/2015-07-16/2825228 Mongodb I've heard about it a few years ago, just know it's a nosql database, knowing that the storage format is JSON and is a file database. MongoDB supports sharding: Concrete implementation: http://my.oschina.net/ydsakyclguozi/blog/268377 PostgreSQL

SQL Server Performance Tuning entry (graphic version) Step 1: capture sample data during business peaks(About 2 hours ). The tool used is the profiler that comes with sqlserver, also known as the event probe. For example, after entering, click the button on the leftmost side to create a new trail: DBO permission is required for logon, therefore, you can log on with SA or use Windows integrated verification

PHP is a scripting language executed on the server side that has developed many of the world's best-known websites, including Yahoo and Facebook. Here are 6 PHP code, performance tuning tips. 1. Upgrade PHP to the latest version The easiest way to improve performance is to constantly upgrade and update the PHP versio

One of the practical skills that can greatly improve the performance of SQL TUNING optimization. When we perform SQL optimization, we often encounter the need to sort a large number of datasets and then retrieve the first part of the results from the sorted set. In this case, when we write SQL statements according to the general idea, the system first reads and filters all sets, then sorts them, and then ex

performance, and to control their sum within the value specified by the Sga_target. Once you assign a value to Sga_target (the default is 0, that is, ASMM is not started), the ASMM feature is started automatically.iii. Oracle Memory tuning approachWhen a performance problem arises in the production environment of a pr

Tags: mysql, mariadb1. Performance1) Performance improvementMySQL5.7 provides more consistent linear performance and scalability on systems that support multi-processor and highly concurrent CPU threads. The key to achieving this is to eliminate InnoDB kernel contention and mutex locking through the concurrency of the efficiency of the Oracle InnoDB storage engin

columns are now collected. This digest is from the core idea of SQL optimizationThe core idea of SQL optimizationRobinson Huang Chao ZhongClick on the cover to buy a paper bookThe Structured Query Language (structured query language,sql) is a powerful database language. It is based on the relational algebra operation, the function is rich, the language is concise, the use is convenient and flexible, has become the relational database standard language. This book is designed to guide reade

Oracle SQL Tuning Oracle's SQL tuning is a complex topic, and even a whole book is needed to introduce the nuances of Oracle SQL tuning. But there are some basic rules that every Oracle DBA needs to follow, and these rules can im

performance analysis and tuning. Background knowledge Main methods of performance analysis Monitoring: Monitoring is a common way to view the run-time behavior of an application. There are often multiple views (view) that display CPU usage, memory usage, thread state, and other useful information in real time, so that users can quickly discover the key to the

1m-2m size, and then set it individually on demand in each session. 4, Read_rnd_buffer_size For sorting and order by operations, it is best to set it to 1M and then set it as a session variable to a larger value in the session. (v) Slow query log A slow query log is a useful feature of MySQL. 1, Log_slow_queries MySQL parameter in the log_slow_queries parameter set it in the My.cnf file, set it to on, by default, MySQL will put the file into the data directory, the file is named "Hostname-slow.

SQL Optimization Oracle SQL optimization is a complex topic, and even requires the entire book to introduce the nuances of Oracle SQL optimization. However, there are some basic rules that every Oracle DBA must follow. These rules can improve the performance of their systems. The goal of SQL optimization is simple: . E

The SQL Tuning toolset (SQL Tuning set,sts) is an integral part of the Oracle 10g SQL Tuning Advisor feature. Each tuning toolset contains one or several SQL statements, as well as the contextual information needed to properly interpret them. SQL

Preface In the past decade, Oracle has become one of the world's most professional databases. For IT experts, it is to ensure that their company's productivity is improved by leveraging the powerful features of oracle. One of the most effective methods is to use ORACLE optimization. It has a lot of parameters and technologies to improve the

rownumObviously, this writing will result in reading the table first, then sorting, and then taking the first 5 records, the plan is as follows:If we write like this, the semantics are the same, but it saves a lot of reading and sorting costs:Select/*+ Index (T1,IDX1_T1) */* from T1 where rownumThe execution plan for this SQL is as follows:As you can see, the SQL does not follow the hint instructions and sequentially scans the IDX1_T1 index, which is why? Personally, it may be that the

In the past decade,OracleIt has become one of the most professional databases in the world. For IT experts, IT is to ensure that their company's productivity is improved by leveraging the powerful features of Oracle. One of the most effective methods isOracle Optimization. It has a lot of parameters and technologies to improve the performance of your Oracle datab

When Oracle database performance problems occur, it is effort-saving to use the Oracle toolkit and give reasonable optimization suggestions. The following two packages are described and their specific practices. The smallest adjustment tool for SQL Tuning Advisor. Use one or more SQL statements as the input content, an

Oracle 11g has made some improvements in optimization. Oracle automates the following optimization: Redo Logfile Sizing Advisor-this feature recommends Redo the optimal size of log files to avoid excessive disk I/O caused by frequent checkpoints. Automatic Checkpoint Tuning-Oracle database can now optimize checkp

% When the full time began to implement the old generation of garbage collection (CMS), then there is still 10% of the space is 5500*10%=550 trillion, so even if xmn (that is, the young generation of 500 trillion) all the objects are moved to the old generation, 550 trillion of space is enough, so as long as the above formula is satisfied, There will be no promotionfailed at the time of garbage collection;SOFTREFLRUPOLICYMSPERMB This parameter I think it might be a bit of a use, the official exp