Yes; optimizing is perfectly normal and safe. WordPress Optimize does not use any trickery or undocumented dangerous processes.
WordPress Optimize uses database clean-up scripts with well-defined, common MySQL commands. Nevertheless, we always recommend backups, which cover every possibility; not just database malfunctions, but hackers, human errors, etc.
I’m afraid that this is not possible. Please ensure that you make a backup of your entire database before using WP-Optimize for the first time, and when you upgrade to a major new version of it. We recommend UpdraftPlus.
For a detailed walk-through on how to use the WP-Optimize Database Cleaning feature, we put together a video that takes you through all the necessary steps:
This is rare; it’s probably because you’re with a shared web hosting company that doesn’t allow scripts to run an optimize command via SQL statements (SQL “OPTIMIZE” instruction). Please consult your web hosting company on this matter.
Over time your WordPress database accumulates extra data such as revisions and spam comments and many more.
Removing this unnecessary data from the database will help reduce your database size and speed up your site.
The process of optimization is the removal of these unwanted/old database entries and the reorganising of the remaining data and associated indexes.