What is Metadata?
Metadata is data that describes other data in a structured, consistent way, so that large amounts of data can be collected, stored, and analyzed over time.
Metadata is needed for storing big data in data warehouses for easy retrieval and management. A data warehouse uses structured data that is standardized, cleaned and consistent across data sources. The metadata ensures uniformity in the collection and storage of this data, so that business owners and data analysts can easily access and gain insights from the data.
The effective management of metadata is an essential part of solid and flexible big data "ecosystems" in that it helps companies more efficiently manage their data assets and make them available to data scientists and other analysts.
Examples of Metadata
As an example, you might have an object like a contact in your database. You would use metadata to describe the data you've collected for this contact, such as Joe Smith (name), ABC Co. (company), 123-456-7890 (phone number). This makes it easier to search your database for contacts that match your search criteria (e.g., all contacts who work at ABC Co.).
When you take a picture on your phone, your mobile device attaches metadata to the photo (e.g., date and time, file size, image dimensions). Social media allows you to tag people and locations in your photos, which adds even more metadata. It will be useful to go back to your photo archive and search for photos by date, location, or person.