From BC$ MobileTV Wiki
(Redirected from ERD)
Jump to: navigation, search

A database is a storage mechanism for raw data which adheres to a certain format or number of possible formats. There are various types of databases, ranging from File Systems to text-based lists, or from full fledged DBMS's to Triple-stores following formats such as RDF or N3.



Extract, Transform, and Load (ETL) is a common organizational process or task for a Database Administrator. It typically involves obtaining (extracting) data from outside sources or disparate internal sources, converting or otherwise massaging (transforming) that data to fit operational needs which could include quality levels, filtering and/or mapping to integrate with other data sources or data points, and lastly moving the data (loading) into the end target database or other data archiving/storage system such as an Operational Data Store (ODS), Data Mart (DM), or Data Warehouse (DW/DWH/EDW).

[1] [2] [3]


Entity Relationship Diagram (ERD) is a type of diagram which describes inter-relations between things of interest in a specific domain of knowledge. It takes standard tabular data and associates it together. The support for ERDs (typically via Primary Key & Foreign Key relationships) is what differentiates a regular DBMS from an RDBMS. Within an ERD, the "ER model" is comprised of entity types (which classify the things of interest) and specifications of relationships that can exist between instances of those entity types. In software engineering an ER model is commonly formed to represent things that a business needs to remember in order to perform business processes. Consequently, the ER model becomes an abstract data model that defines a data or information structure that can be implemented in a database, typically a relational database.

Data Lakes

Data Lakes are systems for long-term data storage for raw/unprocessed data formats such as JSON, XML, PDF, CSV, Excel, etc.

Data Warehouses

Data Warehouses (DW or DWH), also known as an Enterprise Data Warehouse (EDW) are systems for long-term data storage for data from various databases and/or data sources which has already undergone some form of ETL and/or more basic archival & journaling processes (validation, redaction, joins/mergers, "expiration" shelf-life timestamping, etc).




External Links


  1. ETL vs Pure SQL: (Talend Open Studio .vs. SQL Server performance)
  2. ETL vs ELT -- The Difference is in the "How":
  3. What is Reverse ETL: A Definition & Why It's Taking Off:
  4. Get the sample databases for ADO.NET code samples:
  5. Northwind Traders relational data sample:
  6. Install Northwind Traders database and apps:
  7. Northwind Database Explained:

See Also

DBMS | SQL | SQL Schema | NoSQL | BigData