I am trying to understand what ElasticSearch exactly does when it comes to persistence.
When I index documents in ElasticSearch, I also within this step save them within ElasticSearch. Though the reason I index my documents with ElasticSearch is to be able to search for them using the API and certain search algorithms.
Then, within for the rest of my application, I also have a relational database where I store a lot of stuff concerning my application. Within the relational database I also have the same documents I index in ElasticSearch.
As a result I have the documents saved in both ElasticSearch and the relational database. I learend about ElasticSearch to get extended search abilities, but now I wonder whether the step of saving the documents in ElasticSearch and the relational database isn't a bit redundant.
Would it be wise to delete the documents from the relational database and use the indexed documents in ElasticSearch as the data source?