From the course: Advanced SQL for Data Scientists

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Federated queries

Federated queries

From the course: Advanced SQL for Data Scientists

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Federated queries

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- [Instructor] Now, there may be times we want to work with data that's not in the database, and we don't actually want to load the data either, but we'd still like to have access to it through SQL. In that case, we could use something known as federated queries. Now, federated data is data that's outside a database, but is still accessible by SQL. This is made possible by a SQL standard called SQL/MED, or management of external data. And it defines a number of different abstractions, but the sort of key ones are foreign data wrappers and datalinks. Now, a foreign data wrapper is a specification and a module or a package that allows us to view data that's outside the database. Datalinks compliment foreign data wrappers. They provide functionality we expect to have in a database like integrity, functions, recovery mechanisms, and authorization mechanisms. So, the way we create a federated data source is first we create an…

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