Few of the circumstances are listed below where EAV scores over conventional tables:
· The data type of individual attributes varies. Like in above example EAV is used because the requirements vary from client to client like some may want an extra address like added to existing address format.
· The categories of data are numerous, growing or fluctuating, but the number of instances (records/rows) within each category is very small. Here, with conventional modeling, the database’s Entity-Relationship Diagram might have hundreds of tables: the tables that contain thousands/ millions of rows/instances are emphasized visually to the same extent as those with very few rows. The latter are candidates for conversion to an EAV representation.
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