• Explain the status values of SQL Server: runnable, running, suspended, sleeping


    During the management, monitoring and performance tuning of SQL server, we may execute the following SQL instructions to observe the status of SQL Server: SELECT * FROM sys.sysprocesses; EXEC sp_who2; SELECT sqltext.TEXT, req.session_id, req.status, req.command, req.cpu_time, req.blocking_session_id, req.total_elapsed_time FROM sys.dm_exec_requests req (NOLOCK) CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS sqltext As shown in Figure 1, there is a […]

  • Leetcode Weekly – 172 – 4


    1326. Minimum number of taps for irrigating Gardens Hi, everyone. I’m a pig. Welcome to the weekly leetcode quiz of the “baby can understand” series. This is question 4 of issue 172 and 1326 of the list of questions – “minimum number of taps for irrigation gardens.” Title Description There is a one-dimensional garden on […]

  • [Greenplum FAQ] “what if my SQL is stuck?”


    ​Hello, I’m an after-sales engineer of the pivotal Greenplum team. Usually help our global business users to solve database related problems. In practical work, we are often asked by the database administrator: “my SQL has run for a long time without results, how can I troubleshoot?” “what if one SQL of the database is stuck?” […]

  • The difference between jQuery Ajax’s readyState and status and its usage


    In the previous several articles, I analyzed the Ajax asynchrony and synchronization of jQuery, as well as some handling of exceptions. I feel that I haven’t clarified the readyState and status of Ajax. Let’s talk about the Ajax state today. The source code of jQuery Ajax function is as follows: var getXmlHttpRequest = function () […]

  • Analysis of PostgreSQL pg_ctl start start start timeout


    I. Problems When pg_ctl start starts, it exits incorrectly:pg_ctl:server did not start in time。 What is the overtime time? From when to which stage is the timeout? 2. Analysis: The location of this information is printed, as can be seen from the do_start function in the following code snippet 1. After pg_ctl start calls start_postmaster […]