How to fix if there is no such engine: mysql2 in Magento 2.1.10?

Magento Errors: no such engine

Magento 2.1.10 contains almost 40 security fixes and functional enhancements so it will bring a lot of benefits of
your online store owner to upgrade to this latest version.

Solution

I also did that some days ago for my clients, but I encountered a strange error.

Catalog Search indexer process unknown error: There is no such engine: mysql2

After doing some research, I figured out this process to sort out the above issue according to these steps:

# run this query
UPDATE core_config_data set value = 'mysql' where path='catalog/search/engine';
# and run these commands
php -f bin/magento setup:upgrade
php -f bin/magento cache:flush
php -f bin/magento indexer:reindex

I hope this small tip can save you the time of upgrading to the latest Magento 2.1.10 version.