Checking the database

I’m writing a series of posts about migrating out Data Warehouse Database from MySQL version 5.6 to 5.7
(ultimately 5.8). Yesterday I did a test to check the present database, I wrote a script checking all tables
(little less than 4000) in 10 parallel streams, it did not go well, after some 4 hours and still 2500 tables to
check I cancelled the check tables script. Some tables took more than 30 minutes to medium check.
Maybe I’m checking to many in parallel, anyway I decided not to go for a medium check but a quick check
I test this Sunday night.

<?xml version='1.0' encoding='UTF-8' standalone='yes'?> <schedule>   <job name='checkTables'>      <forevery chunks='10' parallel='yes'> <sql>SELECT a.table_schema DB,a.table_name TB    FROM information_schema.tables a    WHERE  a.TABLE_TYPE = 'BASE TABLE'; </sql>      </forevery>      <myiterator piggyback='forevery'/>      <sql> CHECK TABLE @DB.@TB MEDIUM;      </sql>   </job> </schedule>

Why do I do this? Before the migrate it is good to know that all tables are ok, but I cannot wait some 10 to
15 hours for the check to finish.