Database Notes Essay
Specialized structures that allow computer-based systems to store, manage, and retrieve data very quickly. Data are raw facts. Information Is the result of processing raw data to reveal Its meaning. To reveal meaning, information requires context. Raw data must be properly formatted for storage Data constitute the building blocks of information. Information is produced by processing data. Information Is used to reveal the meaning of data. Accurate, relevant, and timely Information Is the key to good decision making. Good decision making Is the key to organizational survival In a global environment.
A database management system (DB’S) is typically used to implement and manage the contents of a database A database is a shared, integrated computer structure that stores a collection of: End-user data-?that is, raw facts of interest to the end user. Metadata, or data about data, through which the end-user data are integrated and managed. A database will typically contain: The collected data “data about the data” (Metadata) Database design defines the structure of a database Traditional Types of Databases (Reads) MS Access MS SQL Server: developed by Microsoft.
Does not support wide variety of platforms MS SQL Azure IBM DB Myself: open source database management system. Can run on SO X system, Linux, etc. Oracle READS Noses (Not only SQL) – not based on the traditional relational DB model MongoDBCouchDBCassandra, etc. A Spreadsheet Is Not a Database It does not support even the most basic database functionality such as support for self-documentation through metadata, enforcement of data types or domains to ensure consistency of data within a column, defined relationships among tables, or constraints to ensure consistency of data across related tables.
Big Data Data Visualization Machine Learning unstructured Data Analytics Cassandra (Faceable) and Vegetable (Google) are using “columnar-database” technologies to support the needs of database applications that manage large amounts of “nontaxable” data Big Data – Garter’s 3 Positively Volume Variety TeraPetaExaZettaYottaData Driven Decision-Making Traditional Enterprise Approach: HIPPO? Highest Paid Person’s Opinion) Data-Driven Approach: A/B testing: a randomized experiment with two variants, A and B, which are the control and treatment in the controlled experiment. Version A might be the currently seed version (control), while Version B is modified in some respect (treatment). Experimentation Big Data Sources Sensor Data: Lethe Internet of Things (TOT) The data dictionary provides a detailed description of all tables in the database created by the user and designer.
Thus, the data dictionary contains at least all of the attribute names and characteristics for each table in the system. In short, the data dictionary contains metadata-?data about data. An implementation-ready data model should contain at least the following components: ; A description of the data structure that will store the end-user data. A set of enforceable rules to guarantee the integrity of the data. ; A data manipulation methodology to support the real-world data transformations.
Chapter 4 A relationship degree indicates the number of entities or participants associated with a relationship. A unary relationship exists when an association is maintained within a single entity. A binary relationship exists when two entities are associated. A ternary relationship exists when three entities are associated. в?Chapter 6 Normalization Normalization: a process for evaluating and correcting table structures to minimize ATA redundancies, thereby reducing the likelihood of data anomalies.
Normal Forms 2 is better than,3 is better than 2. Usually 3 could see as the highest NFG for business. The higher the normal form, the more relational Join operations you need to produce a specified output;Denationalization produces a lower normal form; that is, a INFO will be converted to a INFO through denationalizations attribute that is at least part of a key is known as a prime attribute instead of the more common term key attribute. A neoprene attribute, or a monkey attribute, is not part of any candidate key.