performance

问题 using (StreamWriter writer = File.CreateText(FinishedFile)) { int lineNum = 0; while (lineNum < FilesLineCount.Min()) { for (int i = 0; i <= FilesToMerge.Count() - 1; i++) { if (i != FilesToMerge.Count() - 1) { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("", CurrentFile); writer.Write(CurrentLine + ","); } else { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("",

问题 Env. OS:macOS Mojave Version 10.14.5(centOS have same problem) Springboot:2.1.6.RELEASE(embedded tomcat 9.0.21),war My native language is not english，please forgive my poor english。 I am a new player of SpringBoot, which I think is helpful to build my project. Now I have finish my work with it,But a strange phenomenon harass me. My project cost about 5 minutes to response first request, it cost 5 minutes not 5 seconds, the request after first sames normally。It was extraordinary slow, So I

问题 Env. OS:macOS Mojave Version 10.14.5(centOS have same problem) Springboot:2.1.6.RELEASE(embedded tomcat 9.0.21),war My native language is not english，please forgive my poor english。 I am a new player of SpringBoot, which I think is helpful to build my project. Now I have finish my work with it,But a strange phenomenon harass me. My project cost about 5 minutes to response first request, it cost 5 minutes not 5 seconds, the request after first sames normally。It was extraordinary slow, So I

问题 I created a view named 'myview' as below. create view myview as select 'a' source,col1,col2 from table_a union select source,col1,col2 from table_b ; table_a has an index on col1 , table_b has an index on source , col1 . When I query on myview as below, no index is used. select * from myview where source = a and col1 = 'xxx' ; How do I make the indexes work on this query? Create Code CREATE TABLE `table_a` ( `col1` VARCHAR(50) NULL DEFAULT NULL, `col2` VARCHAR(50) NULL DEFAULT NULL, INDEX

问题 Preload may not be the correct term... I have a page which loads a very large image. I wanted to wait for the large image to completly load before displaying on the page for the user. At the moment, I have a loading gif and i'm using javascript to wait for the image to load and then replace the loading gif src with the image: <img src="loading.gif" id="image" /> <script> img = 'very_large_image.jpg'; var newimg = new Image(); newimg.src = img; newimg.onload = function(){ $('#image').attr('src

问题 Preload may not be the correct term... I have a page which loads a very large image. I wanted to wait for the large image to completly load before displaying on the page for the user. At the moment, I have a loading gif and i'm using javascript to wait for the image to load and then replace the loading gif src with the image: <img src="loading.gif" id="image" /> <script> img = 'very_large_image.jpg'; var newimg = new Image(); newimg.src = img; newimg.onload = function(){ $('#image').attr('src

问题 Is there a list of the different data structures and their big-O access times for Python? I was rummaging through the standard library docs and didn't see any, hence the question. :-) 回答1: It's not in the manual, it's here on the python wiki. The table also includes complexities for methods for the data structures as well. Thanks for asking, I'd never seen this before until I looked for it. 来源： https://stackoverflow.com/questions/4755221/list-of-big-o-analysis-for-python-datastructures

问题 Is there a list of the different data structures and their big-O access times for Python? I was rummaging through the standard library docs and didn't see any, hence the question. :-) 回答1: It's not in the manual, it's here on the python wiki. The table also includes complexities for methods for the data structures as well. Thanks for asking, I'd never seen this before until I looked for it. 来源： https://stackoverflow.com/questions/4755221/list-of-big-o-analysis-for-python-datastructures

问题 Is there a list of the different data structures and their big-O access times for Python? I was rummaging through the standard library docs and didn't see any, hence the question. :-) 回答1: It's not in the manual, it's here on the python wiki. The table also includes complexities for methods for the data structures as well. Thanks for asking, I'd never seen this before until I looked for it. 来源： https://stackoverflow.com/questions/4755221/list-of-big-o-analysis-for-python-datastructures

问题 So I have this question from my professor, and I can not figure out why vector2 is faster and has less cache misses than vector1 . Assume that the code below is a valid compilable C code. Vector2: void incrementVector2(INT4* v, int n) { for (int k = 0; k < 100; ++k) { for (int i = 0; i < n; ++i) { v[i] = v[i] + 1; } } } Vector1: void incrementVector1(INT4* v, int n) { for (int i = 0; i < n; ++i) { for (int k = 0; k < 100; ++k) { v[i] = v[i] + 1; } } } NOTE: INT4 means the integer is 4 Bytes