Detailed time profile for SQL query execution

1. View profile settings

  SHOW VARIABLES like '%profil% '

The results are as follows: profiling off

2. Open profile

  SET Profiling=1

Results:

3. Execute the SQL you want to execute

Explain select* ...

4. Query execution of SQL

  SHOW PROFILES

Results:

5. View the required SQL execution details

   for 308

Results:

   for 308

Results:

   All  for 308

Results:

Status

Hecking table	Checking the data table (this is automatic).
Closing tables	The modified data in the table is being flushed to disk, and the tables that have been exhausted are being closed. This is a quick operation, and if not, you should confirm that the disk space is full or that the disk is under heavy load.
Connect out	Replication from the server is connecting to the primary server
Copying to TMP table on disk	Saving memory by converting temporary tables from memory storage to disk storage because the temporary result set is larger than tmp_table_size
Creating tmp table	Creating temporary tables to hold partial query results
deleting from Main Table	The server is performing the first part of a multi-table delete and has just deleted the first table.
deleting from reference tables	The server is performing the second part of a multi-table delete and is deleting records from other tables.
Flushing tables	Executing FLUSH TABLES, waiting for other threads to close the data table
Killed	Sends a KILL request to a thread, the thread checks the kill flag bit and discards the next kill request. MySQL checks the kill flag bit in each of the main loops, but in some cases the thread may die in a short period of time. If the line regulation regulation is locked by another thread, the kill request will take effect as soon as the lock is released.
Locked	Locked up by another query.
Sending data	Processing record for SELECT query while sending results to client
Sorting for group	Sorting for GROUP by
Sorting for order	Sorting for ORDER BY
Opening tables	The process should be quick, unless other factors interfere with it. For example, a data table cannot be opened by another thread until the row of the ALTER table or LOCK table statement is complete. Trying to open a table
removing duplicates	A query that is executing a SELECT DISTINCT method is being executed, but MySQL cannot optimize those duplicate records in the previous phase. Therefore, MySQL needs to remove the duplicate records again, and then send the results to the client
Reopen table	A lock on a table is obtained, but it must be changed after the table structure has been modified. The lock has been released, the data table is closed, and the data table is attempting to reopen
Repair by sorting	Repair instructions are being sorted to create an index
Repair with Keycache	The repair instructions are using the index cache to create a new index one by one. It'll be slower than Repair by sorting.
Searching rows for update	The qualifying records are being told to find out to prepare for the update. It must be completed before the UPDATE will modify the relevant records.
Sleeping	Waiting for client to send new request
System Lock	Is waiting to get an external system lock. If you are not currently running multiple mysqld servers requesting the same table at the same time, you can suppress the external system lock by adding the--skip-external-locking parameter
Upgrading lock	Insert DELAYED is trying to get a lock table to insert a new record
Updating	Searching for matching records, and modifying them
User Lock	Waiting for Get_lock ()
Waiting for tables	The thread is notified that the data table structure has been modified and the data table needs to be reopened to obtain a new structure. Then, to be able to reopen the data table, you must wait until all other threads close the table. This notification is generated in the following cases: FLUSH TABLES tbl_name, ALTER table, RENAME table, REPAIR table, ANALYZE table, or OPTIMIZE table
Waiting for handler insert	Insert DELAYED has processed all pending inserts and is waiting for a new request

6. Close Profile Analysis

  SET Profiling=0

Results:

Detailed time profile for SQL query execution