java performance tuning and optimization

libraries correctly in the appropriate scenario. At the same time, the flexible use of algorithms and data structures is also an important part of code optimization.While code optimization is a micro-tuning of performance, a "good" implementation and a "bad" implementation have a significant impact on the system. For example, the same as the implementation of th

described in the previous article, and the same bufferedwrtier and bufferedreader efficiency is also very high. The buffer is used preferentially. Using static methods: Static methods can be used directly without building an instance, and because the method area GC is rarely recycled, and the JVM caches commonly used classes, some common tool classes are more likely to encapsulate static performance. And it is more expressive than function overlo

embedded devices, or memory, hard disk space, etc., by using the method of sacrificing CPU, to obtain the original need more memory or hard disk space to complete the work;3. A very simple time to change the space of the algorithm: the implementation of a, b two variable value exchange. The commonly used algorithm is to use the intermediate variables, and the introduction of additional variables means that more space is to be used, the following algorithm, you can eliminate the intermediate var

, connection pooling, and so on, in the design phase, as appropriate for the business. 2. Code tuning: Development PhaseThis is the developer is most familiar with, do the overloading should have feelings, the same function, good implementation and bad implementation is very far. be careful to avoid deadlocks, dead loops. 3. Database tuning: Development phaseJava programs can connect to a database using JDB

compressing and extending the heap space:-xx:minheapfreeratio: Sets the minimum idle scale for heap space. The default is 40. When the free memory in the heap space is less than this value, the JVM expands the heap space.-xx:maxheapfreeratio: Sets the maximum idle scale for heap space. The default is 70. When the free memory in the heap space is greater than this value, the heap space is compressed and a smaller heap is obtained.When-xms and-xmx are equal, both parameters of-xx:minheapfreeratio

contentIn-depth Java program Performance tuning focuses on Java application optimization methods, techniques and ideas, in-depth analysis of the software design level, code level, JVM virtual machine level optimization methods, t

Tags: implementation mechanism originally page organizes tables based on free article content index ClustFollowing the book on SQL tuning (SQL tuning or SQL optimization) in the essentials of high-performance SQL tuning and case resolution, we talk today about one of the mos

Tags: and fast speaking tuning market buffer way a completely"High-performance SQL Tuning essentials and Case Resolution" a book has been launched, many enthusiastic readers on the contents of the book and some of the specific questions raised questions, because of the numerous readers plus my daily work busy, here on the SQL

timeout; b read timeout; c write timeout);2.2. Parallelization of the serial request;A) use of curl_multi_* ();b) Use the swoole extension. 3. compress the PHP interface output:Using gzip compressionBenefits: Facilitates faster reception of data by client side;Cons: Extra CPU overhead 4. Cache Duplicate content: multiple requests, the content is not changed under the circumstances; 5.smarty Tuning and time window overlap ideas (which can be used in c

:16TAB1 small, TAB2 billion level above, two weeks data in tens of millions of.Lan Hua Main 16:13:22Ok.Orchid Island Main 16:16:29So change the SQL:with T1 as (Select count (t.c1), t.c1,t.c2,t.c3,t.c4,t.c5From Tab1 twhere T.c2 not in (' Val1 ', ' val2 ', ' val3 ', ' val4 ', ' VAL5 ')and C1 is not NULLGroup by T.C1, T.C2,T.C3,T.C4,T.C5)Select T1.c1,t1.c2,t1.c3,t1.c4,t1.c5from T1Where NOT EXISTS (Select/*+ Use_hash (m,n) */M.C1, M.C2,M.C3,M.C4,M.C5from T1 m,tab2 Nwhere N.c2 > Sysdate-14and m.c1 =

I will share 11 practical tips on Java performance tuning and java Tuning Most developers think that performance optimization is a complicated problem and requires a lot of experience a

Become a Java GC expert (5)-Java Performance Tuning principle, gc Tuning Not every program needs optimization. If the performance of a program is the same as expected, you don't have to

weeks data in tens of millions of.Lan Hua Main 16:13:22Ok.Orchid Island Main 16:16:29So change the SQL:with T1 as (Select count (t.c1), t.c1,t.c2,t.c3,t.c4,t.c5From Tab1 twhere T.c2 not in (' Val1 ', ' val2 ', ' val3 ', ' val4 ', ' VAL5 ')and C1 is not NULLGroup by T.C1, T.C2,T.C3,T.C4,T.C5)Select T1.c1,t1.c2,t1.c3,t1.c4,t1.c5from T1Where NOT EXISTS (Select/*+ Use_hash (m,n) */M.C1, M.C2,M.C3,M.C4,M.C5from T1 m,tab2 Nwhere N.c2 > Sysdate-14and m.c1 = N.c1and t1.c2 = M.C2);Orchid Island Main 16:

access, and one point, is the index of the cluster factor, when this value is very high (perhaps a lot of friends notice that Sometimes a SQL logical reading is much larger than the whole table, that's all, even if the data you access is small, it's possible to go through a full table scan, and the cluster factor problem is almost inevitable in the case of many different fields, so, to really master the optimization, We must know and understand the b

11 simple Java performance tuning techniques, java Tuning Most developers naturally think that performance optimization is complex and requires a lot of experience and knowledge. Well,

MySQL performance tuning and Architecture design--9th chapter The performance optimization of MySQL database schema designPreface: Many people think that performance is optimized in the process of writing code (program code or database code), in fact, this is a very big misu

A basic knowledge 1.1 What is the performance Before performance tuning, let's first look at what performance is. As for performance, I think everyone who has studied Java can list a few points or even talk about it. In the book

MySQL performance tuning and Architecture Design-Chapter 1 Performance Design-MySQL Replication and replication Optimization Chapter 1 scalability design-MySQL Replication Preface: MySQL Replication is a unique feature of MySQL. It can completely copy data from one MySQL Server Instance to another MySQL Server Instance

A basic knowledge1.1 What is performanceBefore performance tuning, let's start by understanding what performance is. With regard to performance, I think everyone who has studied Java can list a few points and even talk about it. In the J