|Functions of a DBMS:
- Design: ER
- It is a part of information system which is an orchestrated
dynamic operations of an organization, it includes collection,
storing and managing information necessary for business
- A balance between advancement and obsolescence is crucial,
and a database must have the power of transformations to
accommodate any changes in during business operations.
SQL developer provides some design tool design and create
db from scratch.
ER Modeling In use: Crow's feet represents many-side relations
- Indexing With SQL you may create and index
on a very large table to retrieve rows quickly, using ROWID. As
indexes and tables both are synched, DML operations like INSERT,
UPDATE, DELETE, slow down processes and may corrupt the table. The
primary or Foreign Keys are implicit "indexes", the indexes created
with SQL statements are explicit indexes.
SQL-Views A view is virtual table or a stored query
can be created from a single table, multiple tables or from another view.
SQL > CREATE VIEW e_view AS
SELECT eid, empname, job
Limiting or regulating users role and privileges, and protecting
database from any data corruption or damages.
- Authorize actions like :Read, Insert, Update, alter or
- Manage code module to enforce security on the procedures and
impose constraints to reduce the chances of data corruptions.
- Integrity: Check
on referential integrity, non-key integrity, matching correct data
- Concurrency :
avoid undesired duplications or redundancies, preventing users from
interfering with each other while using the same data sources.
- Lock: locking
table or row to defer other users, when the same is being
checked out by another user.
- Versioning :Keeping track of any revision or upgrade of the
- Resolve conflicting data
- Backup/Recovery: Backing up the db and keeping transaction log
- Master Table: Final master table
- Forward log : Updated record
- Backward log :Record in the past
- Transaction : Transactions details like time and the users,
affected row etc.