OLTP (OS) vs OLAP (DW, BI)

On Line Transaction Processing (Operational System)
-Source of data: Operational data; OLTPs are the original source of the data.
-Purpose of data: To control and run fundamental business tasks
-What the data: Reveals a snapshot of ongoing business processes
-Inserts and Updates: Short and fast inserts and updates initiated by end users
-Queries: Relatively standardized and simple queries Returning relatively few records
-Processing Speed: Typically very fast
-Space Requirements: Can be relatively small if historical data is archived
-Database Design: Highly normalized with many tables
-Backup and Recovery: Backup religiously; operational data is critical to run the business, data loss is likely to entail significant monetary loss and legal liability
-Mostly updates
-Many small transactions
-Mb-Tb of data
-Clerical users
-Up-to-date data
-Consistency, recoverability critical
-Bottleneck: maybe cpu

On Line Analytical Processing (Data Warehouse)
-Source of data: Consolidation data; OLAP data comes from the various OLTP Databases
-Purpose of data: To help with planning, problem solving, and decision support
-What the data: Multi-dimensional views of various kinds of business activities
-Inserts and Updates: Periodic long-running batch jobs refresh the data
-Queries: Often complex queries involving aggregations
-Processing Speed: Depends on the amount of data involved; batch data refreshes and complex queries may take many hours; query speed can be improved by creating indexes
-Space Requirements: Larger due to the existence of aggregation structures and history data; requires more indexes than OLTP
-Database Design: Typically de-normalized with fewer tables; use of star and/or snowflake schemas
-Backup and Recovery: Instead of regular backups, some environments may consider simply reloading the OLTP data as a recovery method-Mostly reads
-Queries long, complex
-Gb-TB of data
-Decision-makers, analysts as users
-summarized, consolidated data
-Bottleneck: maybe I/O

Others:
HBA (host bus adapter) connects a host system (the computer) to other network and storage devices. The terms are primarily used to refer to devices for connecting SCSI, Fibre Channel and eSATA devices, but devices for connecting to IDE, Ethernet, FireWire, USB and other systems may also be called host adapters.