vix strategies

separately in the transaction of the new database connection, in which case, If the database supports sequences, you can use Seqhilo.5, using the identity, native, Generationtype.auto and other ways to generate the primary key, as long as the use of the self-increment field, the database table field must be set to automatically increase, or error.6, there are some methods are not listed, such as Uuid.hex,sequence-identity, and so on, these methods are not very common, and has been replaced by o

deal with streaming data and do not want to write Pojo, eventually written in this ugly piece of code, I think the efficiency can be guaranteed.After writing the code, I think the most appropriate JSON library should still be json.simple, its conversion is simple, can be directly based on the string get to the desired information, and the most important is the short code write, the implementation of high efficiency. In the enterprise, in the school, in the face of the intersection anywhere, wit

developers, and it is the distribution problem that causes the system to fail.3. The drawbacks and advantages of memory fragmentationDisadvantages:A large amount of memory fragmentation can make the system slow, because the use of virtual memory makes the data exchange between memory and hard disk known as SystemSlow roots , eventually causing the depletion of memory !Advantages:Reduce memory fragmentation, increase allocation speed, facilitate memory management, and prevent memory leaks4, how

interview. He believes that the interviewer's personal skills and personality experience will affect the outcome of the interview, the interview is full of accidents. Of course, the interview through the full conditions are still some, the author most value is the algorithm and data structure.The author of Google's development process is perfect: There are strict unit testing, design documents, code review, code base uniform, as from one person's hand, the manager at least half the time to writ

#include Results:110082148800f3fb7000821488C + + Program design basics, programming abstraction and algorithm strategydeclaring function pointers------C + + Program design basics, programming abstractions and algorithmic strategies

a Linux Three scheduling strategies for the kernel:1,sched_other time-sharing scheduling strategy,2,sched_fifo Real-time scheduling strategy, first-come-first service. Runs continuously once the CPU is occupied. Keep running until a higher priority task arrives or abandons itself3,SCHED_RR Real Time scheduling strategy, time slice rotation. When the time slice of the process is exhausted, the system will redistribute the time slices and place them at

First understand what a namespace is, a namespace is a "named-and-object" mapping, implemented in Python with Dict.The scope, however, refers to namespaces that can be accessed directly.When we access a variable, we will follow the order of LEGB to lookup: L->local. That is, local variables, such as variables defined in def or lambda. E-> enclosing function locals. That is, the variable in the closure. G->global (module). Global variables. B->built-in. Built-in variables, su

First understand what a namespace is, a namespace is a "named-and-object" mapping, implemented in Python with Dict.The scope, however, refers to namespaces that can be accessed directly.When we access a variable, we will follow the order of LEGB to lookup: L->local. That is, local variables, such as variables defined in def or lambda. E-> enclosing function locals. That is, the variable in the closure. G->global (module). Global variables. B->built-in. Built-in variables, su

controller either inherited Abstractcontroller or implements Controller interface. Httprequesthandleradapter handles Httprequesthandler type of handler, such as: SPRINGMVC in the request through Dispatcherservlet can not find resources, when the default servlet is set, will be handled by Defaultservlethttprequesthandler. Refer to "Spring MVC static Resource Processing"Simpleservlethandleradapter (to be added)6. Inithandlerexceptionresolvers Request exceptionOfficial documentation roughly descri

a themeresolver.There are 3 implementation theme classes in SPRINGMVC: Fixedthemeresolver (default): fixed-format theme, which cannot dynamically change theme while the system is running. Sessionthemeresolver: You can dynamically adjust the value of theme by changing the corresponding key value in the cookie in the run. Cookiethemeresolver: You can dynamically adjust the value of theme by changing the corresponding key value in the session during Operation The topic load p

survivor spaces is used as a rotational backup, so when a large number of objects survive after the minor GC, the old age is most needed for distribution guarantees, Let the survivor space can not accommodate the object directly into the old age.Averaging is still a means of dynamic probability, which means that if a minor GC survives a sudden increase, much higher than the average, it will still lead to a guarantee failure (handlepromotionfailure). If there is a handlepromotionfailure, then yo

, Facebook, Microsoft and other companies are suffering, received their developers frequently visited the Web site. These sites were affected by malicious JavaScript and redirected to implement malware installations on the developer's computer, and the hacked computers became the springboard for attacking companies. Lesson: Let employees recognize that some popular "watering holes" will often be the target of attackers. 　　7. Induction and jump One of the