Data Warehousing and Industry One of the hottest topic in IS Over 90% of larger companies either have a DW or are starting one Warehousing is big business $2 billion in 1995 $3.5 billion in early 1997 $8 billion in 1998 [Metagroupl over $200 billion over next 5 years
9 Data Warehousing and Industry • One of the hottest topic in IS. • Over 90% of larger companies either have a DW or are starting one. • Warehousing is big business – $2 billion in 1995 – $3.5 billion in early 1997 – $8 billion in 1998 [Metagroup] – over $200 billion over next 5 years
Data Warehousing and Industry(2) A 1996 study of 62 data warehousing projects showed An average return on investment of 321% with an average payback period of 2.73 years WalMart has largest warehouse 900-CPU, 2,700 disk, 23 TB Teradata system NTTB in warehouse 40-50GB per day 10
10 Data Warehousing and Industry (2) • A 1996 study of 62 data warehousing projects showed: – An average return on investment of 321%, with an average payback period of 2.73 years. • WalMart has largest warehouse – 900-CPU, 2,700 disk, 23 TB Teradata system – ~7TB in warehouse – 40-50GB per day
What is a data Warehouse? Defined in many different ways non-rigorously A DB for decision support Maintained separately from an organizations operational database a data warehouse is a subjiect-oriented integrated time-variant, and nonvolatile collection of data in support of management's decision-making process.-- W.H. Inmon o Data warehousing The process of constructing and using data warehouses
11 What is a Data Warehouse? • Defined in many different ways non-rigorously. – A DB for decision support. – Maintained separately from an organization’s operational database. • A data warehouse is a subject-oriented, integrated, time-variant, and nonvolatile collection of data in support of management’s decision-making process.— W. H. Inmon • Data warehousing: – The process of constructing and using data warehouses
Why Data Warehousing? Advance of information technology Data collected in huge amounts Need to make good use of data? Architecture and tools to Bring together scattered information from multiple sources to provide consistent data source for decision support. Support information processing by providing a solid platform of consolidated, historical data for analysis
12 Why Data Warehousing? • Advance of information technology. • Data collected in huge amounts. • Need to make good use of data? • Architecture and tools to – Bring together scattered information from multiple sources to provide consistent data source for decision support. – Support information processing by providing a solid platform of consolidated, historical data for analysis
Why Data Mining? Data explosion problem Automated data collection tools and mature database technology Leading to tremendous amounts of data stored in databases, data warehouses and other information repositories o We are drowning in data, but starving for knowledge
13 Why Data Mining? • Data explosion problem: – Automated data collection tools and mature database technology. – Leading to tremendous amounts of data stored in databases, data warehouses and other information repositories. • We are drowning in data, but starving for knowledge!