performance

问题 I am using VSCode for more than a year and never faced this problem. The project I am working on is huge and VSCode is extremely slow when I am working on this project. I tried other projects and they work fine but what's strange is on the same project, a team of 10+ is working and most of them use VSCode but there seems no problem with their VSC. I have to wait for like 2 minutes on first access to IntelliSense. So every time I open a file, I have to wait for like 2 to 3 minutes before I can

问题 Say, I want to create a list quickly which contains 1000 elements. What is the best way to accomplish this? 回答1: You can use Collections.nCopies. Note however that the list returned is immutable. In fact, the docs says " it the newly allocated data object is tiny (it contains a single reference to the data object) ". If you need a mutable list, you would do something like List<String> hellos = new ArrayList<String>(Collections.nCopies(1000, "Hello")); If you want 1000 distinct objects, you

问题 I just found that our current database design is a little inefficient according to the SELECT queries we perform the most. IBANs are positional coordinates, according to nation-specific formats. Since we mostly perform JOIN s and WHERE s on a precise substring of IBAN columns in some tables, my question is about assigning an index to the substring(s) of a column Are we forced to add redundant and indexed columns to the table? Ie. add columns NATION_CODE , IBAN_CIN , IT_CIN , IT_ABI , IT_CAB ,

问题 Here is the code I've stumbled across: class TransactionContextHolder { private static final ThreadLocal<TransactionContext> currentTransactionContext = new NamedInheritableThreadLocal<TransactionContext>( "Test Transaction Context"); static TransactionContext getCurrentTransactionContext() { return currentTransactionContext.get(); } static void setCurrentTransactionContext(TransactionContext transactionContext) { currentTransactionContext.set(transactionContext); } static TransactionContext

问题 I'm trying to understand why Parallel.For is able to outperform a number of threads in the following scenario: consider a batch of jobs that can be processed in parallel. While processing these jobs, new work may be added, which then needs to be processed as well. The Parallel.For solution would look as follows: var jobs = new List<Job> { firstJob }; int startIdx = 0, endIdx = jobs.Count; while (startIdx < endIdx) { Parallel.For(startIdx, endIdx, i => WorkJob(jobs[i])); startIdx = endIdx;

问题 I'm trying to understand why Parallel.For is able to outperform a number of threads in the following scenario: consider a batch of jobs that can be processed in parallel. While processing these jobs, new work may be added, which then needs to be processed as well. The Parallel.For solution would look as follows: var jobs = new List<Job> { firstJob }; int startIdx = 0, endIdx = jobs.Count; while (startIdx < endIdx) { Parallel.For(startIdx, endIdx, i => WorkJob(jobs[i])); startIdx = endIdx;

问题 This feels like a silly question, but what do the various numbers mean on react-native performance monitor? I haven't been able to find in the docs. I understand RAM. What are the others? What do the two separate numbers mean for Views? Is that frames per second? What should I read to in order to become competent on how to use this tool? How reliable is this tool? What benchmarks should I be aiming for? 回答1: Thanks @diedu for posting a link (to a post, which has a comment w/ this youtube vid)

问题 When you use the SQL Server TOP clause in a query, does the SQL Server engine stop searching for rows once it has enough to satisfy the TOP X needed to be returned? Consider the following queries (assume some_text_field is unique and not set for full-text indexing): SELECT pk_id FROM some_table WHERE some_text_field = 'some_value'; and SELECT TOP 1 pk_id FROM some_table WHERE some_text_field = 'some_value'; The first query would need to search the entire table and return all of the results it

问题 When you use the SQL Server TOP clause in a query, does the SQL Server engine stop searching for rows once it has enough to satisfy the TOP X needed to be returned? Consider the following queries (assume some_text_field is unique and not set for full-text indexing): SELECT pk_id FROM some_table WHERE some_text_field = 'some_value'; and SELECT TOP 1 pk_id FROM some_table WHERE some_text_field = 'some_value'; The first query would need to search the entire table and return all of the results it

问题 According to Marcin Ciura's Optimal (best known) sequence of increments for shell sort algorithm, the best sequence for shellsort is 1, 4, 10, 23, 57, 132, 301, 701..., but how can I generate such a sequence? In Marcin Ciura's paper, he said: Both Knuth’s and Hibbard’s sequences are relatively bad, because they are defined by simple linear recurrences. but most algorithm books I found tend to use Knuth’s sequence: k = 3k + 1, because it's easy to generate. What's your way of generating a