The relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data <answer>by content</answer>, rather than by following links. The relational model employs sets of ledger-style tables, each used for a different type of entity. Only in the mid-1980s did computing hardware become powerful enough to allow the wide deployment of relational systems (DBMSs plus applications). By the early 1990s, however, relational systems dominated in all large-scale data processing applications, and as of 2015[update] they remain dominant : IBM DB2, Oracle, MySQL and Microsoft SQL Server are the top DBMS. The dominant database language, standardised SQL for the relational model, has influenced database languages for other data models.[citation needed]
Instead of using links, how was information found in a relational model?
by content