Tag:Line number

  • [20200814] 8K database maximum line number.txt


    [20200814] 8K database maximum line number.txt –//Yesterday, I listened to someone else’s class. They wanted to demonstrate the blocking and deadlock caused by insufficient ITL slots. They said that the maximum line number of the data block in Oracle 8K should not exceed 736–//It is more accurate to say that one block (block size 8K) […]

  • The problem of line number in MySQL


    1. Line number problem Row numbers are consecutive integers that are assigned sequentially to rows in a query result set. The support of MySQL database in line number is not very friendly. There is no similar row provided by other databases_ Number solution, so getting the line number is a very tricky problem. 2.1 analysis […]

  • Linux file view command


    File view command     1. Cat: displays the contents of the file from the first line Usage: cat file or file path For example: cat ifcfg-eth0 or cat / etc / sysconfig / network scripts / ifcfg-eth0 Parameters: -A: The integration option equivalent to – vt can list some special characters instead of blanks; […]

  • C ා completion port (IOCP)


    Pool /// ///Associated with each customer socket, the parameters required for send and receive delivery /// public class IoContextPool { List pool; // assign a socketasynceventargs to each socket client, manage it with a list, and create it when the program starts. Int32 capacity; // pool the capacity of the object pool Int32 boundary; // […]

  • Excel related


    Xlrd openpyxl Library It should be brought with me. Anyway, I didn’t install it. You can also make a form of CSV. I’ll introduce it later basic operation   import xlrd book = xlrd.open_workbook(‘filename’) book.nsheets #Number of forms book.sheet_ Names() ා form name To read the data in a cell in a form, you must […]

  • Devexpress gridcontrol usage


    1、 Common properties 1) Remove “drag a column header here to group by that column” on the GridView header     gridView.OptionsView.ShowGroupPanel = false; 2) It shows the search function of GridView     gridView.OptionsFind.AlwaysVisible = true; 3) Keep column heads from moving     gridView.OptionsCustomization.AllowColumnMoving = false; 4) Disallow sorting of column headers   […]

  • How to view Linux Log quickly?


    Because there are many problems in the production environment, the fastest way to locate is to look at the logs. We all know that the server will generate a large number of logs every day, so how to quickly locate is the key. This paper introduces six commands to view logstail、head、cat、more、less、sed。 1tail 1.1 command function […]

  • Introduction to Valgrind


    Exercise 4: introduction to Valgrind Exercise 4: introducing Valgrind Translator: Flying Dragon Now it’s time to introduce another tool. In the process of learning C, you will use it all the timeValgrind。 I’ll introduce you nowValgrindBecause from now on, you’ll use it in the section “how to make it crash.”.ValgrindIt’s a program that runs your […]

  • MS SQL transaction output error


    begin try    sentence end trybegin catch    –ERROR_ Number() returns the error number.  –ERROR_ Severity() returns the severity.  –ERROR_ State() returns the error status number.  –ERROR_ Procedure() returns the name of the stored procedure or trigger in which the error occurred.  –ERROR_ Line() returns the line number in the routine that caused the error. […]

  • OSD kill succeeded for process


    Environment: Oracle 12.2 single RAC + RedHat 6.9 Em13c error: At / home / u01 / APP / Oracle / diag / RDBMS / DB6 / db61 / Alert/ log.xml Operation error (OSD kill success…): Sun Mar 15 23:23:40 2020 / 67198. alert log: 2020-03-15T23:23:40.022325+08:00Process 0x0x403c7de50 appears to be hung in Auto SQL Tuning taskCurrent […]

  • Java uses IO stream to read files and display them to console 1


    package com.io.exam; import java.io.FileReader; import java.io.IOException; /** *Without line number */ public class TextFileExam { public static void main(String[] args) { //1. Create an instance of FileReader and open the specified file at the same time FileReader fileReader = null; try { FileReader = new FileReader (“read file path”); //2. Read the content of the […]

  • Java uses IO stream to read files and display them to console 2


    package com.io.exam; import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; /** *On behalf of the bank * */ public class TextFileExamLine { /* *Choose to do: improve the program, after reading the file content, add the line number at the beginning of each line, and then output to the screen together with the content. *Tip: the read […]