Failed to migrate from WordPress to Ghost on Heroku

I have a wordpress site, but as the content grows, the site often breaks down, so I'm planning to migrate my wp site to ghost blog.

First, I need to create a ghost blog.The latest version of ghost blog has been updated to V4. This tutorial can meet the needs.

I found that the ghost blog also uses jawsdb-maria as database（same as my existing wp site）.So I backed up the whole wp site using mysqldump -h host -u usr -ppassword database > backup.sql command，Then use the mysql -h host -u usr -ppassword database < backup.sql command to restore the backup content to ghost blog，end in failure. Although the code runs without errors, it doesn't seem to work.

So I found another way. The most important step is how to export the content of the wp site into a file usable by ghost blog.I followed this tutorial,The export process may require reading a lot of internal space. I tried several times, but all ended in failure. The wp site would crash, and then jump to the wordpress installation page. Heroku background log shows: Has exceeded the 'max_questions' resource (current value : 3600 heroku).

That's the price to pay for using free resources, and finally I gave in and stopped looking for ways to migrate wp sites, and instead posted content from the old wp site to the new ghost blog one by one.