How does relationships between tables in a database reduce data redundancy?
“Data redundancy occurs in database systems which have a field that is repeated in two or more tables. For instance, in case when customer data is duplicated and attached with each product bought then redundancy of data is a known source of inconsistency, since customer might appear with different values for given attribute.[1] Data redundancy leads to data anomalies and corruption and generally should be avoided by design.[2] Database normalization prevents redundancy and makes the best possible usage of storage.[3] Proper use of foreign keys can minimize data redundancy and chance of destructive anomalies.[2] However sometimes concerns of efficiency and convenience can result redundant data design despite the risk of corrupting the data.[4]” That was taken from wikipedia In the case outlined above you have a customer table and an order table, instead of duplicating the customers data into the order table, you would (in this case) create a foreign key such as a field called “customeri
