performance profiling

1. Show variables like '%profiling% ';(View profiling information)2. Set profiling=1; (Turn on profiling)3. Execute SQL query Example: Select Goods_name from Ecs_goods where goods_id 4. Show profile for query 4;The format of show profile is as follows:SHOW profile [Type [, type] ...] [for QUERY N] [LIMIT row_count [off

the listThere are at least three ways to traverse after JDK1.5: ForEach, iterator, for loop.Package Bupt.xiaoye.charpter2.list;import Java.util.arraylist;import Java.util.iterator;import java.util.List; public class Testfor {public static void Testforeach (List list) {Object Temp;for (object t:list) temp = t;} public static void Testfor (List list) {Object temp;for (int i = 0; i The result of the operation is:As you can see, the direct for loop is the most efficient, followed by iterators and f

For C ++: Memory analysis tools: 1. c ++ Memory Leak Detector-memory validator (http://www.softwareverify.com/index.html) 2. Other as references: purify from IBM Performance profiling tools: For C #: Memory analysis tools: As developers, we are often faced with addressing memory leaks in our applications. despite the fact that. net Framework events des automatic memory management, a number of memory all

.jhat: Analyze Jmap dump out of the heap to provide access in the form of Web pages. The Jhat function is basically weaker, is very memory-intensive, is largely unusable in the case of large heap files (for example, over 1G), and Eclipse Memory Anaylzer is an excellent alternative. Use the following format:jhat {DumpFile} requires additional startup parameters when the heap file is large, such as the following jhat–j-mx512m {dumpfile}Access http://localhost:7000 to see the results after analysis

, "IsEOF": 1, "Invalidates": 0, "Direction": "Forward", "Docsexamined": 866283 }, "TS": Isodate ("2016-06-04t03:57:10.206z"), "Client": "127.0.0.1", "AllUsers": [ ], "User": ""}Use the following command to view the latest recordsDb.system.profile.find (). Sort ({$natural:-1})There is also a more concise way to viewShow profileThis command can view the last 5 recordsThe information content provided by profile is explainedTS: When the command i

Perf profiling analysis program performancePerf profiling analysis program performance Program Performance Analysis Perf collects call stacks of a program at a certain frequency and performs statistical analysis on the call stacks. If a code path appears more ordinary in the collection result, it means that the program

MySQL performance profiling tool (pt-query-digest) This tool is also from percona-toolkitOther tools in this tool setTroubleshooting of abnormal shutdown of MySQL Slave (pt-slave-restart)Verify MySQL master-slave consistency (pt-table-checksum pt-table-sync)It can analyze various logs to analyze performance issuesIncluding1. Slow log (default)2. tcpdump3. genera

concurrency situation, and if a transaction updates the record, the B transaction update fails.We can't help but ask, what if I want to update the primary key field? Is it wrong to update to more than one record? The answer is yes, it is sure to be incorrectly updated to other records, so LINQ specifies that the primary key field is not allowed to update, if it is true to update, then delete the record and reinsert the new record. Such a rigorous SQL statement will bring us some trouble, let's

MySQL Performance Profiling Tool (pt-query-digest) is also from percona-toolkit Other tools in this tool set Troubleshooting of abnormal shutdown of MySQL Slave (pt-slave-restart) Including 1. slow log (default) 2. tcpdump 3. general log 4. binlog 5. show processlist The experiment simulates a certain amount of pressure through tpcc, and enables binlog, general log, slow log, and tcpdump to collect log

Tags: class mysq tor http profile sharing optimization online toolTo optimize a query, we need to know exactly where this query's performance bottleneck is, is it consuming too much CPU, or does it require too many IO operations? To be able to understand this information clearly, in MySQL 5.0 and the MySQL 5.1 official version can be very easy to do, that is, through the Query Profiler function.MySQL's query Profiler is an easy-to-use Query diagnostic

Tag: Init row off SSI time down table function valueFirst, show profilesSee if the Profiles feature is turned on mysql> show variables like ‘profiling‘; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | profiling | OFF | +---------------+-------+ 1 row in set (0.03 sec) Open profiles in the current session mysql> show variables like ‘

Day 3 (11/17/2010) Step 3: Practice1. find an Animation demo (requires a bit of attention, rich pixels, and faster Animation speed to improve the difficulty of the Screen Display), and add a timer in it, modify the RenderOptions of the current process at intervals. processRenderMode, the Code is as follows: Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--> Timer timer = new Timer ();Timer. Interval = 500; // change once in half a secondT

why resources become inefficient: 1, excessive use of resources, insufficient balance; 2, the resources are not properly matched; 3, resource damage or failure 3.5 Other Profiling Tools User_statistics: Some tables measure and audit database activity Strace: Investigate system invocation situations, use real time, unpredictable, overhead,oprofile use CPU cycles Summary: The most effective way to define perf