Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
The definition of schema is logical structure of data in database. It is owned by a user and has the same name as the database user. The schema contains name of table, what is it’s column type etc. And the data dictionary also contains metadata only (offcourse it is at database level and not at user level). What is the exact difference between schema and data dictionary?
These definitions are from my experience (programmer for 20+ years, 7 years in consulting, some time as an independent contractor). YMMV.
“Schema” describes structure. It might include metadata that describes aspects of the structure.
A “data dictionary” associates context with elements of the structure. It also might include metadata that describes aspects of relationships.
For example, A ‘person’ might be described by the usual fields – last_name, first_name, honorific, etc. If there is a relationship to another person – father, husband, etc – those values might be considered “schema data” because the relationships are constrained by specific values.
That the ‘person’ is a ‘student’ or a ‘teacher’ or a ‘prisoner’ etc – that is defined by the data dictionary for the particular system.