How Amazon Bedrock ensure that customer knowledgebase are isolated and stored

Please review the Security section in the FAQ page here: https://aws.amazon.com/bedrock/faqs/ Each knowledgebase will be using a dedicated vector database you choose to use from the options available to you in your account.

You can choose a vector database like Amazon OpenSearch Serverless, Amazon Aurora, MongoDB Atlas, Pinecone or Redis Enterprise Cloud. These resources are created in your account and you will be able to view them in the native console for each. They have the same security you would have when using any of the storage/database services.