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C175 - Data Management Foundations
Data Management Foundations (Western Governors University)
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, lOMoARcPSD|28964921
C175 Data Management Foundations
Notes
Downloaded by john gatheca ()
, lOMoARcPSD|28964921
Lesson 1 - Introduction to Databases, Information,
and Data
Why Databases?
- Databases are the best way to store and manage data as persistent and shareable in a
secure way.
File Structures
- Prior to Database Management Systems, information was initially stored in file-based
systems. Small amounts of information are easy to retrieve from a file-based system.
- The speed that information can be retrieved from a file depends on the structure of the
file, and on how the data is organized in that structure.
- Flat files
- Files having no internal hierarchy
- Heap files
- Files containing an unsorted set of records that are uniquely identified by a
record id, which allows them to be inserted or delete using that id.
- Index files
- Files that store a list of lookup field values from a data file — along with the
location (address) in the data file of the corresponding record.
- Because the lookup field is much smaller than the entire record, the entire index
will usually fit in main memory for quick look up.
- Once the address of the record is obtained from the index, the entire record can
be directly accessed from the data file instead of reading in the entire data file.
- Hashed files
- Files are encrypted using hash functions that convert data consisting of various
formats into numeric values. This allows for faster data lookup without the use of
an index file.
Downloaded by john gatheca ()
, lOMoARcPSD|28964921
Data Versus Information
- Data
- Consists of raw facts.
- The raw facts have not yet been processed to reveal their meaning.
- Information
- The result of processing raw data to reveal its meaning.
- Can be as simple as organizing data to reveal patterns or as complex as making
forecasts or drawing inferences using statistical modeling.
- Raw data must be properly formatted for storage, processing, and presentation.
- Knowledge
- The body of information and facts about a specific subject
- Implies familiarity, awareness, and understanding of information as it applies to
an environment.
- New knowledge can be derived from old knowledge.
- Data constitutes 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.
- Data Management
- a discipline that focuses on the proper generation, storage, and retrieval of data.
Downloaded by john gatheca ()
C175 - Data Management Foundations
Data Management Foundations (Western Governors University)
Studocu is not sponsored or endorsed by any college or university
Downloaded by john gatheca ()
, lOMoARcPSD|28964921
C175 Data Management Foundations
Notes
Downloaded by john gatheca ()
, lOMoARcPSD|28964921
Lesson 1 - Introduction to Databases, Information,
and Data
Why Databases?
- Databases are the best way to store and manage data as persistent and shareable in a
secure way.
File Structures
- Prior to Database Management Systems, information was initially stored in file-based
systems. Small amounts of information are easy to retrieve from a file-based system.
- The speed that information can be retrieved from a file depends on the structure of the
file, and on how the data is organized in that structure.
- Flat files
- Files having no internal hierarchy
- Heap files
- Files containing an unsorted set of records that are uniquely identified by a
record id, which allows them to be inserted or delete using that id.
- Index files
- Files that store a list of lookup field values from a data file — along with the
location (address) in the data file of the corresponding record.
- Because the lookup field is much smaller than the entire record, the entire index
will usually fit in main memory for quick look up.
- Once the address of the record is obtained from the index, the entire record can
be directly accessed from the data file instead of reading in the entire data file.
- Hashed files
- Files are encrypted using hash functions that convert data consisting of various
formats into numeric values. This allows for faster data lookup without the use of
an index file.
Downloaded by john gatheca ()
, lOMoARcPSD|28964921
Data Versus Information
- Data
- Consists of raw facts.
- The raw facts have not yet been processed to reveal their meaning.
- Information
- The result of processing raw data to reveal its meaning.
- Can be as simple as organizing data to reveal patterns or as complex as making
forecasts or drawing inferences using statistical modeling.
- Raw data must be properly formatted for storage, processing, and presentation.
- Knowledge
- The body of information and facts about a specific subject
- Implies familiarity, awareness, and understanding of information as it applies to
an environment.
- New knowledge can be derived from old knowledge.
- Data constitutes 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.
- Data Management
- a discipline that focuses on the proper generation, storage, and retrieval of data.
Downloaded by john gatheca ()
