1

I want to retrieve phone_num and their count of unread message for each phone number from the table user_message. Below mentioned query takes 10 seconds to give result which is super duper slow for me.

Extra Info of table:

  1. I have Indexed Column phone_num and user_message_id
SELECT phone_num,
       Count(phone_num) AS no_of_messages
FROM   user_message
WHERE  user_message_id = "rd62tdw4n3"
       AND msg_status = "unread"
GROUP  BY phone_num 
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  • Did you consider adding an index for columns user_message_id, msg_status?
    – SaschaM78
    Mar 25, 2022 at 10:52

1 Answer 1

2

You need a compound index as follows

ALTER TABLE user_message
ADD INDEX covering_index (user_message_id,msg_status,phone_num);

The query will read everything from this index and never touch the table

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  • Thanks @RolandoMySQLDBA . It worked ! Mar 25, 2022 at 11:12

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