I am planning to install JSS package on my sitecore instance to use GraphQL APIs. I want to know wether installing JSS package change/alter my database schema or solr indexes. In case I want to uninstall the JSS package later, will it be a clean uninstall or it will impact my db also?
JSS does not alter the SQL database schema. Sitecore modules rarely, if ever, do. It does install a number of items and alters permissions on
/sitecore/content. It does not directly alter the Solr indexes, but the managed schema may be updated based on the additional templates and items included in the JSS module.