Collection of concepts, technique, and processes for the proper identification, definition, and management of data elements within an organization.

Measurements that assess company’s effectiveness or success in reaching goals. KPIs are determined after the main strategic, tactical, and operational goals are defined for a business.

Mostly stored in a relational database. Optimized to support transactions representing daily operations.

differs from operational data in three main areas:

•         Time span

•         Granularity

•         Dimensionality

Integrated, subject-oriented, time-variant and non-volatile collection of data.

1. Provides support for decision making.

2. Usually a read-only database optimized for data analysis and query processing.

Maps multidimensional decision support data into relational database.

represent specific business aspects or activity

Normally stored in a fact table that is center of star schema

Data are processed and viewed as part of a multidimensional structure.

Data are processed and viewed as part of a multidimensional structure.

Advanced data access feature include:

•         Access to many different kinds of DBMSs, flat files, and internal and external data sources.

•         Access to aggregated data warehouse data.

An analytical interface that permits the user to navigate the data in a way that simplifies and accelerate decision making or data analysis.

A subset of business intelligence functionality that encompasses a wide range of mathematical, statistical, and modelling techniques.

it is a tools that do the following:

•         Analyze data.

•         Uncover problems or opportunities hidden in data relationships.

•         Form computer models based on their findings.

•         Use models to predict business behavior

•         Requires minimal end-user intervention.

Refers to the use of advanced mathematical, statistical, and modeling tools to predict future

A set of databases in a distributed system that can appear to applications as a single data source.

A set of databases in a distributed system that can appear to applications as a single data source.

shared among two or more physically independent sites that are connected through a network.

shared among two or more physically independent sites that are connected through a network.

stores a logically related database over two or more physically independent sites. The sites are connected via a computer network.

a subset of distributed database.

Software component of a system that requests data. Known as application processor (AP) or the transaction manager (TM).

Software component on a system that stores and retrieves data from its location.

Processing is done on a single host computer.

Multiple processes run on different computers that share a single data repository. Requires a network file server running conventional applications. Accessed through LAN

Reduces network traffic., Processing is distributed., Support data at multiple sites.

Roll transactions back and forward with the help of the system’s transaction log entries.

Forces the log entry to be written to permanent storage before actual operation takes place.

Forces the log entry to be written to permanent storage before actual operation takes place.

delay imposed by the amount of time required for a data packet to make a round trip.

delay imposed when nodes become suddenly unavailable due to a network failure.

How to partition database into fragments.

Which fragments to replicate.

Where to locate those fragments and replicas.

Division of relation into subsets (fragments) of tuples (rows).

Division of a relation into attribute (column) subsets.

Division of a relation into attribute (column) subsets.

Combination of horizontal and vertical strategies.

Stores multiple copies of each database fragment at multiple sites.

Stores multiple copies of some database fragments at multiple sites

Stores each database fragment at a single site.

SQL performance tuning: Generates SQL query that returns correct answer in least amount of time. Using minimum amount of resources at server.

DBMS performance tuning: DBMS environment must be configured properly to respond to clients’ requests as fast as possible. Optimum use of existing resources.

DBMS finds the most cost-effective access path without user intervention.

Requires that the optimization be selected and scheduled by the end user or programmer.

Requires that the optimization be selected and scheduled by the end user or programmer.

Best optimization strategy is selected when the query is compiled by the DBMS. It takes place at compilation time.

Access strategy is dynamically determined by the DBMS at run time, using the most up-to-date information about the database.

based on a set of user-defined rules to determine the best query access strategy

refers to a number of measurements about database objects, such as number of processors used, processor speed, and temporary space available.

The DBMS parses the SQL query and chooses the most efficient access/execution plan.

The DBMS executes the SQL query using the choses execution plan.

The DBMS fetches the data and sends the result set back to the client.

Analyzes SQL query and finds most efficient way to access data.

DBMS-specific and translate client’s SQL query into series of complex I/O operations.

Help speed up data access. Facilitate searching, sorting, using aggregate functions and join operations.

number different values a column could have.

Five components typically causes bottlenecks:

used to implement indexes:

Hash index, B-tree index,Bitmap index

used to implement indexes:

Hash index, B-tree index,Bitmap index

Uses preset rules and points to determine the best approach to execute a query.

Uses algorithms based on statistics about objects being accessed to determine the best approach to execute a query.

special instructions for the optimizer, embedded in the SQL command text.

Store large portions of the database in primary memory.