Simply you can just start with the StartUp plan and upgrade anytime whenever there is a need to do so.
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Siteground allows the creation of an unlimited number of MySQL & PostgreSQL Databases which can then be easily managed by phpMyAdmin and phpPgAdmin.
If you are in shared hosting, you don’t have to worry about security as each website or application is secured individually, that means security threat on one website on a shared environment will not affect your website or application.
Even more, Siteground has a dedicated team of security experts to mitigate all kinds of security issues 24/7.
Check below video for more explanation.