SEARCH KEYWORD -- Nested if


  How Query Optimizer Works in RDBMS

In a previous post, we discussed how the various relational operators are implemented in relational database systems. If you have read that post, you probably still remember that there are a few alternative implementations for every operator. Thus, how should RDBMS determine which algorithm (or implementation) to use? Obviously, to optimize the performance for any query, RDBMS has to select the correct the algorithm based on the query. It would not be desirable to always use the same algori...

   DATABASE,DATABASE DESIGN,DATABASE OPTIMIZATION     2019-04-20 07:26:32

  Remove duplicated elements in JavaScript array

During interviews, one frequent question asked would be something like how to remove duplicated elements in a JavaScript array and how many different ways you can think of. The interviewee would also be asked to write the code down. In real applications, normally front end would not need to handle this case since normally it would be done by backend, but still it's necessary for front end developers to know different ways of doing this. This post will share some of the common ways to remove dupl...

   JAVASCRIPT,ARRAY,DUPLICATED ELEMENT     2018-09-21 22:32:10

  JSON unmarshal in GoLang

In almost all mainstream programming languages, there is either built-in or third-party library to support parse JSON data because it is so popular for organizing and transferring data among different services. In GoLang, the built in json package also provides functions for marshalling and unmarshalling JSON data. Marshalling GoLang struct to a JSON string is relatively simple, just need to call json.Marshal(), it's a bit complicated to unmarshal an arbitrary JSON string into a GoLang struct ob...

   GOLANG,JSON,UNMARSHAL,EMPTY INTERFACE     2019-11-09 21:57:30

  GCC is compiled with C++ compiler

On 15 Aug, 2012, GCC merged a patch--Merge from cxx-conversion branch . This means GCC will be compiled with C++ compiler in the future, it also means that GCC will be implemented using C++. You may have following two puzzles: Why does GCC turn to C++? Without C++ compiler, how can we compile C++ codes? Why using C++? In GNU's C++ Conversion, we can find this description in the background section: Whether we use C or C++, we need to try to ensure that interfaces are easy to understan...

   GCC,C++,Compiler     2012-09-04 02:36:06

  Go Error Best Practice

Being indulged in Go for quite a while and having implemented web-related programs, grpc interfaces and Operators, I seem to be an advanced beginner now. However, I am still a raw hand in production-environmental debugging, which is cumbersome if done by querying logs or error messages. Imagine the scenario that a full-text search is called when the specific location of the error log is missing. Then what happens when those error logs are not only in one place? Yes, my error logs can no longer h...

   GO ERROR,ERROR HANDLING     2021-10-07 07:38:28

  Memory related exception analysis in Java

Java Virtual Machine Specification divides the memory of JVM into several areas : Heap, Stack, The Program Counter register and Method area etc. In HotSpot JVM, heap is composed of Young, Tenured and Perm. There are different OutOfMemory error can happen in different memory area. Next is an overview of some of these OOM errors. StackOverflowError The JVM will allow only a specified number of stacks created nested. An JVM option -Xss can be set to determine the maximum stack size. If the num...

   Java, Memory model, Memory exception, OOM     2015-01-19 06:54:27

  JavaScript interview questions

This post will cover the JavaScript questions I have encountered and have seen during my programming career. They will mainly focus on vanilla JavaScript though there are lots of excellent frameworks out there and many people are using them in their daily work. this keyword this keyword is an very important but easy to confuse concept in JavaScript since it is always referring to the calling object of the function. 1. What will be the output of below code snippet? function User(name) { this....

   JAVASCRIPT,ALGORITHM,THIS,CLOSURE     2019-03-09 07:05:46

  How small should a function be?

"The well-designed functions are often relatively small, large function design is often a mess or there is a lot of room for optimization."Maybe you think there is no need to discuss the size of functions, because the nature of the function design is cohesive, its size is only its manifestations. But it is necessary to discuss about the size of function because the statement above .First let's understand the concept of minimum code processing unit : a basic operation (assignment, comparison, etc...

   Function size,Optimization     2012-12-18 13:58:07

  Go Lacks Ternary Operators. Here Are Some Equivalents

If you were like me, a pure Java developer before writing Go, you must be wondering why Go doesn’t support the ternary operator like return a > 1 ? 0 : 1. Most mainstream languages like C and Java are supportive of ternary operators; languages like Python and Ruby support the simplified if-else one-liner, such as a = 0 if a > 1. However, Go is not among them. And it is not only about adding operators but also a concept of coding in a more convenient way, such as the ?: expression can...

   GOLANG,TERNARY OPERATOR     2022-12-09 19:51:32

  A Sip of Go Log

Logging is indispensable in any code that we need its support both in debugging and in statistics. However, a package that filled withfmt.Println/fmt.Printf printing various messages can never be considered a read-to-be-adopted package, which can be optimized by a simple change, using Golang’s native log package to print information to standard output or to a file. Then, how to apply the log package? Are there any limitations? If so, can we seek open-source packages? Let&rsq...

   GOLANG,LOGGING     2022-06-16 05:43:24

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