understand scitools

I. Oracle ArchitectureOracle 's architecture is the composition of the database, the work process, and the organization and management of data in the database, to understand The architecture of the Oracle database, you must understand the Oracle The main components and important concepts. the Oracle architecture includes a range of components, including instances, user processes, service processes, data fi

To tell the truth, I did not fully understand the two-point lookup of the various formulations, resulting in the writing of a variety of two-point boundary when I always do not clear the boundary value, so I can only through the violent enumeration of these boundary values, to a test, this is really low efficiency. Therefore, the painful lesson, must be two points of the wording thoroughly understand, there

As we all know, memory management is the most basic and important part of the Linux kernel. Understanding the relevant principles, whether it is the understanding of memory, or for everyone to write user-state code is very helpful. Many books, many articles are written related content, but the individual always feel that the content is too complex, not too easy to understand, here want to use my own understanding of the simple way to describe, hope to

Tags: except example com set AMP Pack console common three layerIf you're using idea for the first time, it's going to be a lot of money to spend it without a purpose. In the sincerity of the table,On an idea teaching video to table my sincerity. (: Https://pan.baidu.com/s/1gfeX3hD)When you persist in using idea for a week, you will really love it, even if the first few days are painful to boil over, in the end you will also really understand why I wi

the Catalog: (drwxrwxrwx)-(d-------W) ==> drwxrwxr-x See, the actual default permissions for the document are that way. Understand this mechanism, we should be able to extrapolate establish their own document default security mechanism, hey. So, how to modify umask , super simple, directly in the back input the permission score, such as:umask 002. By the way, the supervisor process daemon uses this mechanism to protect the child processes, as fo

executes, a represents the memory unit address unchanged, and its value is updated to 2.As for the above Python naming rule, I have written a simple note before , and I will not dwell on it. The above rules are easy to understand, but in actual engineering projects, it is possible to inadvertently introduce bugs to the code by neglecting the " assignment-binding " feature (an experienced C/s code is prone to make this mistake when writing Python code

This is the 10th article in the Solidity Tutorial series, with a full understanding of solidity's function modifier.For a complete list of articles in the solidity series, see Category-solidity.Write in frontSolidity is the Ethereum Smart Contract programming language, you should know about Ethereum and smart contracts before reading this article.If you don't understand, it's recommended that you look at Ethereum first.Functions modifier (function Mod

1. In the Linux 0.11\linux\kernel\exit.c file, either the Send_sig () function or the kill_session () function, the place where the signal is sent is direct (*p)->signal |= 1 What I do not understand is: why the long signal directly in the TASK_STRUCT structure, change the variable bitmap, even if the signal is sent? After sending the signal, there must be a response, how to respond?2.Linux system call is originally called in the user space, how to en

Understand that test instructions is a water problem.Give you n rows each row has 25 characters, the first and last are ' X ', the middle may contain spaces, ask each time with the left (or right) to move, until there is no space in the middle, ask at this time how many spaces.We directly consider the state after the move, it is definitely a small line of the first move, then as long as the total number of the original space minus the minimum space of

How to understand the C4.5 algorithm solves the characteristic problem that the ID3 algorithm is biased to the choice valueConsider an extreme case where the value of a property (feature) is so large that each value corresponds to a category with only one. This is based on \[h (D)-H (d| a) \] to know that the value of the next item is 0. The gain in this information will be very large. The C4.5 algorithm adds a penalty item \[h_a (D) =-\sum_{i=1}^n\df

Everyone, while learning Java, mostly use the IDE environment such as Eclipse, but this is not good, and the package access rights, is also a key step of framework control in Java,Only if you really have to master. The relationship between Java files and the package can really grasp the relationship, and help to write a good framework;Less nonsense, first on the code;This is with the package com.xuyaowen.demo; File, which represents the location of the Jack.java file;Package Com.xuyaowen.demo;pu

This article is translated from Spiral rule and is attached to the full text.Clockwise/Spiral RuleThe clockwise/Spiral rule is a way for any C programmer to understand the program's claims.The following 3 steps:1. Starting with the element to determine the type, replace the following element with the corresponding statement in a clockwise direction, for example:[X] or []==>array X size of ... or Array undefined size of.;(type1,type2)==>function passin

more direct, attention is to find duplicate location. If you do not understand, you can refer to the following code.Five, KMP algorithm implementation1 /*2 return Val means the begin POS of Haystack3 -1 means no matching substring4 */5 intKMP (Char*haystack,Char*needle) {6 //pre-process7 if(haystack[0] ==0 needle[0] ==0)8 return 0;9 Ten intI, J, K, Min, cur; One A //construct F (t) in Vector len -vectorint>Len; -Len.push_back

Prototype in JavaScript has not been very understanding, today after reading the "Advanced JavaScript Programming" finally understand the prototype. To simply summarize what you learned from the book.We all know that after creating a function, this function has a property like prototype, and with this prototype we can do a lot of things, the one thing we often use is to use it as a constructor, so This paper explains prototype from the perspective of

Original: JavaScript Tour-11th station: Prototypes are not good to understand?Write this, my JS series is nearing the end, so this series will not leave JS to achieve the core of object-oriented-prototype, some people say the prototype is not good understanding, in fact, want to systemUnderstanding of the prototype, the most convenient way is to look at the classic book, less read some blog, blog This thing is only Bo Master's own personal understandi

How to understand uiautomator inside the child, Child_by_text, sibling, we use the Android native Uiautomatorviewer crawl control to understandWith a detailed explanation (the left and right sides are circled by different colors, indicating the attribution of these controls), such as the red circle part as a parent class, the green circle and the yellow circle are its subclasses (called Child), and the green and yellow circles belong to the same level

status code: Some pictures and JS files in the local client cache, again after the request, the cached file can be used. 2, above so the HTTP request, only a TCP connection, this is called the persistent connection . Iv. Web application Framework or specification for HTTP protocolJava EE people will know the servlet specification. Where the Web application container implements the objects in the HTTP protocol, the request and response objects. For example, there must be a description

JS files in the local client cache, again after the request, the cached file can be used. 2, above so the HTTP request, only a TCP connection, this is called the persistent connection. Iv. Web application Framework or specification for HTTP protocolJava EE people will know the servlet specification. Where the Web application container implements the objects in the HTTP protocol, the request and response objects. For example, there must be a description of the status code in the Javax.s

write a program that would solve such problems.The input consists of one to the data sets, followed by a final line containing only 0. Each data set starts with a line containing only a number n, which is the number of villages, 1 The output is an integer per line for each data set:the minimum cost of aacms per month to maintain a road system that C Onnect all the villages. Caution:a Brute force solution that examines every possible set of roads would not finish within the one minute time limit

are a lot of questions that are not easy to understand, such as many advanced features, such as meta-classes, generator expressions, descriptors, co-routines, and so on. Python does not have too many places to prescribe how, many usages are just idioms, such as self and what is discussed in this article. These are used either to make the code look more elegant, or to have previous experience. There is no limit to the possibilities of using Python, an