Originally used on a nearly 1.91 million records of in and out of the log tables and records about 20 past migrated to MySQL8 code table, found the query "out into a difference of 1 hour" record, it only takes 30 seconds in used originally can results statements, 10 minutes in MySQL also could not find as a result,
Don't know is what reason, please give analyze, thank you!

SQLServer2012 is performed in 28 seconds


MySQL query for a long time is less than the results

CodePudding user response:

First remove the mysql table primary key and index, and derivative according to; Data after the guide to the new table primary key and index