“…In biomedical data capture and archiving practice, both RDBMS and NoSQL DBMS have been used to build database tools [28,34,38,[60][61][62]. In the RDBMS environment, a particular data structure, EAV, has been a popular strategy to 'boost' database flexibility [24,28,29,45,61]. However, researchers and users soon noticed system performance and data usability problems [29,[63][64][65].…”