Data WareHousing Interview Questions & Answers

Data warehouse questions

2009-11-18T21:38:00.001-08:00

1. List the types of statistics collected for monitoring the functioning of the data

warehouse.

2. Describe any six different types of action for growth planning prompted by the

collected statistics.

3. How do the statistics help in fine-tuning the data warehouse?

4. Do you think publishing the statistics and similar data for the users is helpful? If

so, why?

5. What are the three main subjects in user training content? Why are these essential?

6. Describe any four major tasks needed to prepare a training program.

7. What are the responsibilities of the training administrator?

8. Do you think a multitier user support structure is suitable for the data warehouse

environment? What are the alternatives?

9. What role can the company’s intranet play in training and user support?

10. List any five factors to be part of ETL management.

Evluating Vendor Solutions

2009-11-18T21:17:00.000-08:00

First and foremost, determine the functions in your data warehouse that absolutely

need vendor tools and solutions.

For each type of product you need, carefully list the features that are expected. Divide

the features into groups by importance—high, medium, and low. Use these

groups of features to grade the products you are considering.

Allocate enough time to research available solutions and vendors thoroughly.

If you try to incorporate solutions from too many different vendors, you must be

prepared to face serious challenges of incompatibilities and restrictions for integration.

Stay with two or three vendors whose products are most appropriate for your

needs.

Metadata is a key component of a data warehouse. Ensure that the vendor products

you choose can handle metadata satisfactorily.

The standing and stability of the vendor is equally important as the effectiveness of

the products themselves. Even when the products are suitable for your environment,

if you are concerned about the staying power of the vendor, have second thoughts on

selecting these products.

Never rely solely on vendor demonstrations as the basis for your selection, nor

should you check only the references furnished by the vendors themselves.

Test the tools and products in your environment, with subsets of your own data.

Arrange for both user representatives and IT members of the project team to test the

products, jointly and independently.

Establish a definitive method for comparing and scoring competing products. You

may devise a point system to score the various features you are looking for in a

product type.

The success of your data warehouse rides on the end-user tools. Pay special attention

to the choice of the end-user tools. You may compromise a bit on the other

types, but not on the end-user tools.

Most of your end-users will be new to data warehousing. Good, intuitive and easyto-

use tools go a long way in winning them over.

Users like tools that seamlessly incorporate online queries, batch reporting, and data

extraction for analysis.

Which transformation should we use to normalize the COBOL and relational sources?

2009-09-18T21:22:00.000-07:00

Normalizer Transformation

When U drag the COBOL source in to the mapping Designer workspace,the normalizer transformation automatically appears,creating input and output ports for every column in the source

Difference between static cache and dynamic cache

2009-09-17T21:21:00.000-07:00

Static cache Dynamic cache

U can not inert or update the cache. U can insert rows into the cache as u pass

to the target

The informatic server returns a value from The informatic server inserts rows into cache

the lookup table opr cache when the condition when the condition is false.This indicates that

is true.When the condition is not true,the the row is not in the cache or target table

informatica server returns the default value U can pass these rows to the target table

for connected transformations and null for

unconnected transformations
i

What r the types of lookup caches?

2009-09-16T21:21:00.000-07:00

Persistent cache: U can save the lookup cache files and reuse them the next time the informatica server processes a lookup transformation configured to use the cache

Recache from database: If the persistent cache is not synchronized with he lookup table,U can configure the lookup transformation to rebuild the lookup cache

Static cache: U can configure a static or read-only cache for only lookup table. By default informatica server creates a static cache.It caches the lookup table and lookup values in the cache for each row that comes into the transformation.when the lookup condition is true,the informatica server does not update the cache while it prosesses the lookup transformation

Dynamic cache: If u want to cache the target table and insert new rows into cache and the target,u can create a look up transformation to use dynamic cache.The informatica server dynamically inerts data to the target table

shared cache: U can share the lookup cache between multiple transactions.U can share unnamed cache between transformations inthe same maping

what is meant by lookup caches?

2009-09-15T21:21:00.000-07:00

The informatica server builds a cache in memory when it processes the first row af a data in a cached look up transformation.It allocates memory for the cache based on the amount u configure in the transformation or session properties.The informatica server stores condition values in the index cache and output values in the data cache

Differences between connected and unconnected lookup?

2009-09-14T21:20:00.000-07:00

Connected lookup Unconnected lookup

Receives input values diectly from Receives input values from the result of a

the pipe line. lkp expression in a another transformation

U can use a dynamic or static cache U can use a static cache

Cache includes all lookup columns Cache includes all lookup out put ports in the

used in the mapping lookup condition and the lookup/return port

Support user defined default values Does not support user defiend default values

Why use the lookup transformation ?

2009-09-13T21:20:00.000-07:00

To perform the following tasks

Get a related value. For example, if your source table includes employee ID, but you want to include the employee name in your target table to make your summary data easier to read.

Perform a calculation. Many normalized tables include values used in a calculation, such as gross sales per invoice or sales tax, but not the calculated value (such as net sales).

Update slowly changing dimension tables. You can use a Lookup transformation to determine whether records already exist in the target.

What is the look up transformation?

2009-09-12T21:19:00.000-07:00

Use lookup transformation in u'r mapping to lookup data in a relational table, view, synonym

Informatica server queries the look up table based on the lookup ports in the transformation. It compares the lookup transformation port values to lookup table column values based on the look up condition

What r the join types in joiner transformation?

2009-09-10T21:19:00.000-07:00

Normal (Default)

Master outer

Detail outer

Full outer

What r the settings that u use to configure the joiner transformation?

2009-09-09T21:18:00.000-07:00

Master and detail source

Type of join

Condition of the join

which condtions we can not use joiner transformation(Limitaions of joiner transformation)?

2009-09-08T21:17:00.000-07:00

Both pipelines begin with the same original data source.

Both input pipelines originate from the same Source Qualifier transformation.

Both input pipelines originate from the same Normalizer transformation.

Both input pipelines originate from the same Joiner transformation.

Either input pipelines contains an Update Strategy transformation.

Either input pipelines contains a connected or unconnected Sequence Generator transformation.

What r the diffrence between joiner transformation and source qualifier transformation?

2009-09-07T21:17:00.000-07:00

U can join hetrogenious data sources in joiner transformation which we can not achieve in source qualifier transformation

U need matching keys to join two relational sources in source qualifier transformation.Where as u doesn't need matching keys to join two sources

Two relational sources should come from same datasource in sourcequalifier.U can join relatinal sources which r coming from diffrent sources also

What is aggregate cache in aggregator transforamtion?

2009-09-06T21:17:00.000-07:00

The aggregator stores data in the aggregate cache until it completes aggregate calculations.When u run a session that uses an aggregator transformation,the informatica server creates index and data caches in memory to process the transformation.If the informatica server requires more space,it stores overflow values in cache files

Can u use the maping parameters or variables created in one maping into any other reusable transformation?

2009-09-05T21:17:00.000-07:00

Yes.Because reusable tranformation is not contained with any maplet or maping

Can U use the maping parameters or variables created in one maping into another maping?

2009-09-05T21:16:00.000-07:00

NO

We can use mapping parameters or variables in any transformation of the same maping or mapplet in which U have created maping parameters or variables

What r the mapping paramaters and maping variables?

2009-09-04T21:15:00.000-07:00

Maping parameter represents a constant value that U can define before running a session.A mapping parameter retains the same value throughout the entire session

When u use the maping parameter ,U declare and use the parameter in a maping or maplet.Then define the value of parameter in a parameter file for the session

Unlike a mapping parameter,a maping variable represents a value that can change throughout the session.The informatica server saves the value of maping variable to the repository at the end of session run and uses that value next time U run the session

What r the unsupported repository objects for a mapplet?

2009-09-03T21:15:00.000-07:00

COBOL source definition

Joiner transformations

Normalizer transformations

Non reusable sequence generator transformations

Pre or post session stored procedures

Target definitions

Power mart 3.5 style Look Up functions

XML source definitions

IBM MQ source definitions

What r the methods for creating reusable transforamtions?

2009-09-02T21:15:00.000-07:00

Two methods

1.Design it in the transformation developer

2.Promote a standard transformation from the mapping designer.After U add a transformation to the mapping , U can promote it to the status of reusable transformation

Once U promote a standard transformation to reusable status,U can demote it to a standard transformation at any time

If u change the properties of a reusable transformation in mapping,U can revert it to the original reusable transformation properties by clicking the revert button

What r the reusable transformations?

2009-09-01T21:15:00.000-07:00

Reusable transformations can be used in multiple mappings.When u need to incorporate this transformation into maping,U add an instance of it to maping.Later if U change the definition of the transformation ,all instances of it inherit the changes.Since the instance of reusable transforamation is a pointer to that transforamtion,U can change the transforamation in the transformation developer,its instances automatically reflect these changes.This feature can save U great deal of work

How many ways u create ports?

2009-08-31T21:14:00.000-07:00

Two ways

1.Drag the port from another transformation

2.Click the add button on the ports tab

What is the PivotTable® Service?

2009-08-31T06:52:00.000-07:00

This is the primary component that connects clients to the Microsoft® SQL Server™ 2000 Analysis Server. It also provides the capability for clients to create local offline cubes using it as an OLAP server. PivotTable® Service does not have a user interface, the clients using its services has to provide its user interface.

What r the connected or unconnected transformations?

2009-08-30T21:13:00.000-07:00

An unconnected transformation is not connected to other transformations in the mapping.Connected transformation is connected to other transformations in the mapping

What are offline OLAP cubes?

2009-08-30T06:51:00.000-07:00

These are OLAP cubes created by clients, end users or third-party applications accessing a data warehouse, relational database or OLAP cube through the Microsoft® PivotTable® Service. E.g. Microsoft® Excel™ is very popular as a client for creating offline local OLAP cubes from relational databases for multidimensional analysis. These cubes have to be maintained and managed by the end users who have to manually refresh their data.

What r the active and passive transformations?

2009-08-29T21:13:00.000-07:00

An active transformation can change the number of rows that pass through it. A passive transformation does not change the number of rows that pass through it

What are virtual cubes?

2009-08-29T06:51:00.000-07:00

These are combinations of one or more real cubes and require no disk space to store them. They store only the definitions and not the data of the referenced source cubes. They are similar to views in relational databases.

What r the designer tools for creating transformations?

2009-08-28T21:12:00.000-07:00

Mapping designer

Transformation developer
Mapplet designer

What are MOLAP cubes?

2009-08-28T06:51:00.000-07:00

MOLAP Cubes: stands for Multidimensional OLAP. In MOLAP cubes the data aggregations and a copy of the fact data are stored in a multidimensional structure on the Analysis Server computer. It is best when extra storage space is available on the Analysis Server computer and the best query performance is desired. MOLAP local cubes contain all the necessary data for calculating aggregates and can be used offline. MOLAP cubes provide the fastest query response time and performance but require additional storage space for the extra copy of data from the fact table.

How can U create or import flat file definition in to the warehouse designer?

2009-08-27T21:13:00.000-07:00

U can not create or import flat file definition in to warehouse designer directly. Instead U must analyze the file in source analyzer, and then drag it into the warehouse designer. When u drags the flat file source definition into warehouse designer workspace, the warehouse designer creates a relational target definition not a file definition. If u want to load to a file, configure the session to write to a flat file. When the informatica server runs the session, it creates and loads the flat file

What are ROLAP cubes?

2009-08-27T06:51:00.000-07:00

ROLAP Cubes: stands for Relational OLAP. In ROLAP cubes a copy of data from the fact table is not made and the data aggregates are stored in tables in the source relational database. A ROLAP cube is best when there is limited space on the Analysis Server and query performance is not very important. ROLAP local cubes contain the dimensions and cube definitions but aggregates are calculated when they are needed. ROLAP cubes requires less storage space than MOLAP and HOLAP cubes.

Which transformation should u need while using the COBOL sources as source definitions?

2009-08-26T21:11:00.000-07:00

Normalizer transformation which is used to normalize the data. Since COBOL sources r often consists of Denormailzed data

What are HOLAP cubes?

2009-08-26T06:50:00.000-07:00

HOLAP Cubes: stands for Hybrid OLAP. A ROLAP cube has a combination of the ROLAP and MOLAP cube characteristics. It does not create a copy of the source data however, data aggregations are stored in a multidimensional structure on the Analysis Server computer. HOLAP cubes are best when storage space is limited but faster query responses are needed.

To provide support for Mainframes source data, which files r used as a source definitions?

2009-08-25T21:08:00.000-07:00

COBOL files

What are cubes?

2009-08-25T06:54:00.001-07:00

Cubes are data processing units composed of fact tables and dimensions from the data warehouse. They provide multidimensional views of data, querying and analytical capabilities to clients.

What are aggregations?

2009-08-25T06:53:00.009-07:00

Aggregations are precalculated numeric data. By calculating and storing the answers to a query before users ask for it, the query processing time can be reduced. This is key in providing fast query performance in OLAP.

What are measures?

2009-08-25T06:53:00.008-07:00

Measures are numeric data based on columns in a fact table. They are the primary data which end users are interested in. E.g. a sales fact table may contain a profit measure which represents profit on each sale.

What are fact tables?

2009-08-25T06:53:00.007-07:00

A fact table is a table that contains summarized numerical and historical data (facts) and a multipart index composed of foreign keys from the primary keys of related dimension tables.

What are dimensions?

2009-08-25T06:53:00.005-07:00

Dimensions are categories by which summarized data can be viewed. E.g. a profit summary in a fact table can be viewed by a Time dimension (profit by month, quarter, year), Region dimension (profit by country, state, city), Product dimension (profit for product1, product2).

What is OLTP?

2009-08-25T06:53:00.003-07:00

OLTP stands for Online Transaction Processing.OLTP uses normalized tables to quickly record large amounts of transactions while making sure that these updates of data occur in as few places as possible. Consequently OLTP database are designed for recording the daily operations and transactions of a business. E.g. a timecard system that supports a large production environment must record successfully a large number of updates during critical periods like lunch hour, breaks, startup and close of work.

What is OLAP?

2009-08-25T06:53:00.001-07:00

OLAP stands for Online Analytical Processing.It uses database tables (fact and dimension tables) to enable multidimensional viewing, analysis and querying of large amounts of data. E.g. OLAP technology could provide management with fast answers to complex queries on their operational data or enable them to analyze their company's historical data for trends and patterns.

What is a data warehouse?

2009-08-25T06:52:00.003-07:00

A data warehouse is a collection of data marts representing historical data from different operations in the company. This data is stored in a structure optimized for querying and data analysis as a data warehouse. Table design, dimensions and organization should be consistent throughout a data warehouse so that reports or queries across the data warehouse are consistent. A data warehouse can also be viewed as a database for historical data from different functions within a company.

What are the benefits of data warehousing?

2009-08-25T06:52:00.001-07:00

Data warehouses are designed to perform well with aggregate queries running on large amounts of data.
The structure of data warehouses is easier for end users to navigate, understand and query against unlike the relational databases primarily designed to handle lots of transactions.
Data warehouses enable queries that cut across different segments of a company's operation. E.g. production data could be compared against inventory data even if they were originally stored in different databases with different structures.
Queries that would be complex in very normalized databases could be easier to build and maintain in data warehouses, decreasing the workload on transaction systems.
Data warehousing is an efficient way to manage and report on data that is from a variety of sources, non uniform and scattered throughout a company.
Data warehousing is an efficient way to manage demand for lots of information from lots of users.
Data warehousing provides the capability to analyze large amounts of historical data for nuggets of wisdom that can provide an organization with competitive advantage.

What is a data mart?

2009-08-25T06:51:00.000-07:00

A data mart is a segment of a data warehouse that can provide data for reporting and analysis on a section, unit, department or operation in the company, e.g. sales, payroll, production. Data marts are sometimes complete individual data warehouses which are usually smaller than the corporate data warehouse.

What is the approximate size of a data warehouse?

2009-08-25T06:49:00.000-07:00

You can estimate the approximate size of a data warehouse made up of only fact and dimension tables by estimating the approximate size of the fact tables and ignoring the sizes of the dimension tables.

To estimate the size of the fact table in bytes, multiply the size of a row by the number of rows in the fact table. A more exact estimate would include the data types, indexes, page sizes, etc. An estimate of the number of rows in the fact table is obtained by multiplying the number of transactions per hour by the number of hours in a typical work day and then multiplying the result by the number of days in a year and finally multiply this result by the number of years of transactions involved. Divide this result by 1024 to convert to kilobytes and by 1024 again to convert to megabytes.

E.g. A data warehouse will store facts about the help provided by a company’s product support representatives. The fact table is made of up of a composite key of 7 indexes (int data type) including the primary key. The fact table also contains 1 measure of time (datetime data type) and another measure of duration (int data type). 2000 product incidents are recorded each hour in a relational database. A typical work day is 8 hours and support is provided for every day in the year. What will be approximate size of this data warehouse in 5 years?

First calculate the approximate size of a row in bytes (int data type = 4 bytes, datetime data type = 8 bytes):

size of a row = size of all composite indexes (add the size of all indexes) + size of all measures (add the size of all measures).

Size of a row (bytes) = (4 * 7) + (8 + 4).
Size of a row (bytes) = 40 bytes.

Number of rows in fact table = (number of transactions per hour) * (8
hours) * (365 days in a year).
Number of rows in fact table = (2000 product incidents per hour) * (8
Hours ) * (365 days in a year).
Number of rows in fact table = 2000 * 8 * 365
Number of rows in fact table = 5840000
Size of fact table (1 year) = (Number of rows in fact table) * (Size of a
row)

Size of fact table (bytes per year) = 5840000 * 40
Size of fact table (bytes per year) = 233600000.
Size of fact table (megabytes per year) = 233600000 / (1024*1024)
Size of fact table (in megabytes for 5 years) =
(23360000 * 5) / (1024 *1024)
Size of fact table (megabytes) = 1113.89 MB
Size of fact table (gigabytes) = 1113.89 / 1024
Size of fact table (gigabytes) = 1.089 GB

How many ways U can update a relational source definition and what r they?

2009-08-24T21:09:00.000-07:00

Two ways

1. Edit the definition

2. Re import the definition

3. Where should U place the flat file to import the flat file definition to the designer?

Place it in local folder

While importing the relational source definition from database, what are the metadata of source U import?

2009-08-23T21:08:00.000-07:00

Source name
Database location

Column name
Data types

Key constraints

What are the types of External Loader available with Informatica?

2009-08-22T21:08:00.000-07:00

If you have rank index for top 10. However if you pass only 5 records, what will be the output of such a Rank Transformation?
if u r using a update strategy in any of ur mapping, then in session properties u have to set treat source rows as Data Driven. if u select insert or udate or delete, then the info server will not consider UPD for performing any DB operations.

ELSE

u can use the UPD session level options. instead of using a UPD in mapping just select the update in treat source rows and update else insert option. this will do the same job as UPD. but be sure to have a PK in the target table.

2) for oracle : SQL loader

for teradata:tpump,mload.

3) if u pass only 5 rows to rank, it will rank only the 5 records based on the rank port.

How u will create header and footer in target using informatica?

2009-08-21T21:09:00.000-07:00

If you are focus is about the flat files then one can set it in file properties while creating a mapping or at the session level in session properties
What are mapping parameters and varibles in which situation we can use it
If we need to change certain attributes of a mapping after every time the session is run, it will be very difficult to edit the mapping and then change the attribute. So we use mapping parameters and variables and define the values in a parameter file. Then we could edit the parameter file to change the attribute values. This makes the process simple.
Mapping parameter values remain constant. If we need to change the parameter value then we need to edit the parameter file .
But value of mapping variables can be changed by using variable function. If we need to increment the attribute value by 1 after every session run then we can use mapping variables .
In a mapping parameter we need to manually edit the attribute value in the parameter file after every session run.

Which is better among connected lookup and unconnected lookup transformations in informatica or any other ETL tool?

2009-08-20T21:09:00.000-07:00

f you are having defined source you can use connected, source is not well defined or from different database you can go for unconnected
We are using like that only

Explain about Recovering sessions?

2009-08-18T21:06:00.000-07:00

If you stop a session or if an error causes a session to stop, refer to the session and error logs to determine the cause of failure. Correct the errors, and then complete the
session. The method you use to complete the session depends on the properties of the mapping, session, and Informatica Server configuration.
Use one of the following methods to complete the session:
· Run the session again if the Informatica Server has not issued a commit.
· Truncate the target tables and run the session again if the session is not recoverable.
· Consider performing recovery if the Informatica Server has issued at least one commit.

What is a time dimension? give an example.

2009-08-17T21:05:00.000-07:00

In a relational data model, for normalization purposes, year lookup, quarter lookup, month lookup, and week lookups are not merged as a single table. In a dimensional data modeling(star schema), these tables would be merged as a single table called TIME DIMENSION for performance and slicing data.
This dimensions helps to find the sales done on date, weekly, monthly and yearly basis. We can have a trend analysis by comparing this year sales with the previous year or this week sales with the previous week.

Can u copy the session to a different folder or repository?

2009-08-16T21:05:00.000-07:00

In addition, you can copy the workflow from the Repository manager. This will automatically copy the mapping, associated source,targets and session to the target folder.
Discuss the advantages & Disadvantages of star & snowflake schema?
In a STAR schema there is no relation between any two dimension tables, whereas in a SNOWFLAKE schema there is a possible relation between the dimension tables.

What is difference between stored procedure transformation and external procedure transformation?

2009-08-15T21:05:00.000-07:00

In case of storedprocedure transformation procedure will be compiled and executed in a relational data source.U need data base connection to import the stored procedure
in to u’r maping.Where as in external procedure transformation procedure or function will be executed out side of data source.Ie u need to make it as a DLL to access in u r
maping.No need to have data base connection in case of external procedure transformation.

How to use mapping parameters and what is their use

2009-08-14T21:05:00.000-07:00

In designer u will find the mapping parameters and variables options.u can assign a value to them in designer. comming to there uses suppose u r doing incremental extractions daily. suppose ur source system contains the day column. so every day u have to go to that mapping and change the day so that the particular data will be extracted . if we do that it will be like a layman's work. there comes the concept of mapping parameters and variables. once if u assign a value to a mapping variable then it will change between sessions.

In Dimensional modeling fact table is normalized or denormalized?in case of star schema and incase of snow flake schema?

2009-08-13T21:05:00.000-07:00

In Dimensional modeling, Star Schema: A Single Fact table will be surrounded by a group of Dimensional tables comprise of de- normalized data Snowflake Schema: A Single Fact table will be surrounded by a group of Dimensional tables comprised of normalized dataThe Star Schema (sometimes referenced as star join schema) is the simplest data warehouse schema, consisting of a single "fact table" with a compound primary key, with one segment for each "dimension" and with additional columns of additive, numeric facts.The Star Schema makes multi-dimensional database (MDDB) functionality possible using a traditional relational database. Because relational databases are the most common data management system in organizations today, implementing multi-dimensional views of data using a relational database is very appealing. Even if you are using a specific MDDB solution, its sources likely are relational databases. Another reason for using star schema is its ease of understanding. Fact tables in star schema are mostly in third normal form (3NF), but dimensional tables in de-normalized second normal form (2NF). If you want to normalize dimensional tables, they look like snowflakes (see snowflake schema) and the same problems of relational databases arise - you need complex queries and business users cannot easily understand the meaning of data. Although query performance may be improved by advanced DBMS technology and hardware, highly normalized tables make reporting difficult and applications complex.The Snowflake Schema is a more complex data warehouse model than a star schema, and is a type of star schema. It is called a snowflake schema because the diagram of the schema resembles a snowflake.Snowflake schemas normalize dimensions to eliminate redundancy. That is, the dimension data has been grouped into multiple tables instead of one large table. For example, a product dimension table in a star schema might be normalized into a products table, a Product-category table, and a product-manufacturer table in a snowflake schema. While this saves space, it increases the number of dimension tables and requires more foreign key joins. The result is more complex queries and reduced query performance.
We are using Update Strategy Transformation in mapping how can we know whether insert or update or reject or delete option has been selected during running of sessions in Informatica.
In Designer while creating Update Strategy Transformation uncheck "forward to next transformation". If any rejected rows are there automatically it will be updated to the session log file.
Update or insert files are known by checking the target file or table only.

What is hash table informatica?

2009-08-12T21:05:00.000-07:00

In hash partitioning, the Informatica Server uses a hash function to group rows of data among partitions. The Informatica Server groups the data based on a partition key.Use hash partitioning when you want the Informatica Server to distribute rows to the partitions by group. For example, you need to sort items by item ID, but you do not know how many items have a particular ID number.

What r the joiner caches?

2009-08-11T21:18:00.000-07:00

When a Joiner transformation occurs in a session, the Informatica Server reads all the records from the master source and builds index and data caches based on the master rows

After building the caches, the Joiner transformations reads records from the detail source and perform joins

How can u recover the session in sequential batches?

2009-08-09T21:08:00.000-07:00

If you configure a session in a sequential batch to stop on failure, you can run recovery starting with the failed session. The Informatica Server completes the session and
then runs the rest of the batch. Use the Perform Recovery session property
To recover sessions in sequential batches configured to stop on failure:
1.In the Server Manager, open the session property sheet.
2.On the Log Files tab, select Perform Recovery, and click OK.
3.Run the session.
4.After the batch completes, open the session property sheet.
5.Clear Perform Recovery, and click OK.
If you do not clear Perform Recovery, the next time you run the session, the Informatica Server attempts to recover the previous session.
If you do not configure a session in a sequential batch to stop on failure, and the remaining sessions in the batch complete, recover the failed session as a standalone
session.

Data Warehousing - Introduction

2009-08-08T08:46:00.000-07:00

1. Explain the evolution of database technology to data mining 2 to 5
2. Describe the steps involved in data mining as a process of knowledge discovery 11 to
3. How is a data warehouse different from a database? How are they similar?
4. Briefly describe different advance database systems and their applications.
5. Define different data mining functionalities 53 to 72
6. Define interestingness, and explain the issues related to interestingness 73 to 78
7. Explain the classification of data mining systems 79 to 84
8. Describe the issues pertaining to data mining systems 85 to 94

What kinds of data belong in a data warehouse?

2009-07-02T23:13:00.000-07:00

Data that comes from your mainframe or client/server computing systems, data that you use to manage your business, or any type of data that has value to your business. The idea behind the data warehouse is to capture all types of data into a central location. Once this is done you have the ability to link different types of data together and turn that data into valuable information that can be used for your business needs, analysis, discovery and planning

Why would I want to access the data warehouse when I have a mainframe computing system?

2009-06-29T23:12:00.000-07:00

Your computing system is set up to handle subject specific day to day business and transaction processing, such as payroll or course registration. The reports created in this type of system are specific to the subject matter. The benefits to putting your data into the data warehouse include:
 Merging subject specific data together to create information
 Standardizing data across the University
 Improving turnaround time for reporting
 Lowering costs because you can produce your own reports instead of costly, centrally printed and distributed mainframe reports
 Sharing data or allowing others to easily access your data will free staff from the tasks of extracting data and reporting for other departments or colleges

Definitions of OLAP on the Web:

2009-06-28T02:21:00.000-07:00

On-line retrieval and analysis of data to reveal business trends and statistics not directly visible in the data directly retrieved from a data warehouse. Also known as multidimensional analysis.
www.georgetown.edu/uis/ia/dw/GLOSSARY0816.html
Online Analytical Processing or OLAP provides multidimensional, summarized views of business data and is used for reporting, analysis, modeling and planning for optimizing the business. SQL Server supports OLAP via Analysis Services. Analysis Services can be used to work with data warehouses or data marts designed for sophisticated enterprise intelligence systems. These systems process queries required to discover trends and analyze critical factors. ...
www.yukonxml.com/Glossary/
Online Analytical Processing
www.dmreview.com/resources/glossary.cfm
On-line analytical processing. OLAP is defined as providing fast access to shared multi-dimensional data. OLAP is a term used to generically refer to software and applications that provide users with the ability to store and access data in multi-dimensional cubes. (See also Multi-Dimensional Analysis and Cubes.)
www.oranz.co.uk/glossary_text.htm
On-Line Analytical Processing. A category of applications and technologies for collecting, managing, processing and presenting multidimensional data for analysis and management purposes.
www.olapreport.com/glossary.htm
On-line Analytical Processing. Information analysis that pass the FASMI test: Fast Analysis of Multidimensional Information.
www.intoweb.co.za/it-terms.php
On-Line Analytical Processing. OLAP should be designed to provide end users a quick way of slicing and dicing the data.
www.1keydata.com/datawarehousing/glossary1.html
OLAP (online analytical processing) enables a user to easily and selectively extract and view data from different points-of-view.
www.creotec.com/index.php
“Drilling down” on various data dimensions to gain a more detailed view of the data. For instance, a user might begin by looking at North American sales and then drill down on regional sales, then sales by state, and then sales by major metro area. Enables a user to view different perspectives of the same data to facilitate decision-making.
it.csumb.edu/departments/data/glossary.html
On-Line Analytical Processing, originally introduced in 1994 in a paper by EF Codd, is a decision support counterpart to On-Line Transaction Processing. OLAP allows users to derive information and business intelligence from Data Warehouse systems by providing tools for querying and analyzing the information in the Warehouse. IN particular, OLAP allows multidimensional views and analysis of the data for decision support processes.
planning.ucsc.edu/irps/dwh/DWHGLOSS.HTM
(online analytical processing) A technology that uses multidimensional structures to provide rapid access to data for analysis. OLAP data sets for Project Server are stored in SQL Server tables and managed with Project Web Access and SQL Server Analysis Services. See also: cube
msdn.microsoft.com/library/en-us/pjsdk/html/pjsdkCubesGlossary_HV01096283.asp
A multidimensional, multi-user, client/server computing environment for users who need to analyze consolidated enterprise data in real time. OLAP systems feature zooming, data pivoting, complex calculations, trend analyses, and data modeling.
www-306.ibm.com/software/data/db2/db2olap/docs/v82docs/miner82/glossary.htm
Software that assists in fast analysis of data stored in databases or data warehouses across multiple dimensions.
home.att.net/~c-and-d/Definitions.htm
OLAP is an acronym for online analytical processing. It is an approach to quickly provide the answer to complex database queries. It is used in business reporting for sales, marketing, management reporting, data mining and similar areas. Some people have suggested that an alternative and perhaps more descriptive term to describe the concept of OLAP is Fast Analysis of Shared Multidimensional Information, or FASMI.
en.wikipedia.org/wiki/OLAP

Definitions of decision tree on the Web:

2009-06-27T02:20:00.000-07:00

Definitions of decision tree on the Web:
Is a listing of all the possible outcomes of an expression. Typically decision trees are for boolean expressions.
www.oasismanagement.com/frames/TECHNOLOGY/GLOSSARY/d.html
A graphical representation of all possible outcomes and the paths by which they may be reached; often used in classification tasks. The top layer consists of input nodes (eg, meteorological observations and data). Decision nodes determine the order of progression through the graph. The leaves of the tree are all possible outcomes or classifications, while the root is the final outcome (for example, a weather prediction or climate classification). ...
amsglossary.allenpress.com/glossary/browse
A decision analysis tool that represents multiple collections of rules in the form of branches on a tree, that lead to a larger value or class.
www.bridgefieldgroup.com/glos2.htm
form of flow diagram in which readers are routed according to their response to questions, usually consisting of graphic rectangles and diamonds connected with lines and arrows.
www.techcommunicators.com/dkmanual/glossary.html
A predictive model based on a branching series of tests. Each test examines the value of a single column in the data and uses it to determine the next test to apply. The results of all tests determine which label to predict.
www.purpleinsight.com/downloads/docs/visualizer_tutorial/glossary/go01.html
A diagram consisting of nodes and branches that depicts the information for a decision problem. (page 790)
highered.mcgraw-hill.com/sites/0072470267/student_view0/chapter17/glossary.html
In decision theory (for example risk management), a decision tree is a graph of decisions and their possible consequences, (including resource costs and risks) used to create a plan to reach a goal. Decision trees are constructed in order to help with making decisions.
en.wikipedia.org/wiki/Decision_tree

Definitions of metadata on the Web:

2009-06-26T02:20:00.000-07:00

Data that is used to describe other data. Data definitions are sometimes referred to as metadata. Examples of metadata include schema, table, index, view and column definitions.
www.orafaq.com/glossary/faqglosm.htm
Metadata is information about a particular data set which may describe, for example, how, when, and by whom it was received, created, accessed, and/or modified and how it is formatted. Some metadata, such as file dates and sizes, can easily be seen by users; other metadata can be hidden or embedded and unavailable to computer users who are not technically adept. Metadata is generally not reproduced in full form when a document is printed. ...
www.krollontrack.com/legalresources/glossary.asp
Informational data about the data, included in a signal's data stream.
www.cdtv.ca/en/glossary.htm
data about data. Metadata describes how and when and by whom a particular set of data was collected, and how the data is formatted. Metadata is essential for understanding information stored in data warehouses and has become increasingly important in XML-based Web applications.
www.electronicscriptorium.com/glossary.html
Data about data, or information known about the image in order to provide access to the image. Usually includes information about the intellectual content of the image, digital representation data, and security or rights management information.
www.cdpheritage.org/resource/introduction/rsrc_glossary.html
"data about data" describe the content, quality, condition, and other characteristics of data. Metadata is vital in helping potential users to find needed data and determine whether a data set will meet their needs before they spend the time and money to obtain and process it. This information will often include some of the following:
web2.gov.mb.ca/mli/glossary/m_z.html
Data about data. Index-type information pertaining to the entire data set rather than the objects within the data set. Metadata usually includes the date, source, map projection, scale, resolution, accuracy, and reliability of the information, as well as data about the format and structure of the data set.
atlas.library.arizona.edu/glossaryk_p.htm
Data about data. Includes information describing aspects of actual data items, such as name, format, content, and the control of or over data.
dli.grainger.uiuc.edu/glossary.htm
structured data about data, which may include information about the author, title and subject of web resources. Metadata is added in the section of the webpage or is stored in a database. It is available for searching but is not displayed on the page.
members.optusnet.com.au/~webindexing/Webbook2Ed/glossary.htm
Data about other data, commonly divided into descriptive metadata such as bibliographic information, structural metadata about formats and structures, and administrative metadata, which is used to manage information.
www.cs.cornell.edu/wya/DigLib/MS1999/glossary.html
Summary information regarding other information being presented. Metadata can describe any type of information resource and service, users can gain access to information about resources that are not available on-line for full text searching including: electronic documents, databases, collections of printed books, microforms, government information services, etc. Terms used for the subject field in the Newsroom must be referenced from the Government of Canada Core Subject Thesaurus.
commnet.gc.ca/news_nouvelles/glossary_e.html
(1) Information about a data set which is provided by the data supplier or the generating algorithm and which provides a description of the content, format, and utility of the data set. Metadata provide criteria which may be used to select data for a particular scientific investigation. (2) Information describing a data set, including data user guide, descriptions of the data set in directories, and inventories, and any additional information required to define the relationships among these. ...
podaac.jpl.nasa.gov/glossary/
Data which describes other data. For example, a description of a database in terms of its structure and the relationship between the entities in it. (www.oxford reference.com) Open Access Digital works that are made available often at no cost to the reader on the public Internet for purposes of education and research. (US Association of Research Libraries: www.arl.org)
www.bl.uk/about/strategic/glossary.html
information describing the characteristics of data. Data or information about data. Descriptive information about an organization’s data, data activities, systems, and holdings.
www.sedris.org/glossary.htm
Data (information) about data. Term which describes the data.
web.mit.edu/warehouse/glossary.html
means any additional or bibliographic information about one or more of the data collections, as notified to the End User from time to time. Metadata may be supplied by electronic means.
edina.ac.uk/ukborders/terms.shtml
the reference information about how the data is collected
www.estuaries.gov/glossary.html
Data about data. Metadata in HGL refers to documentation that describes the data layers themselves. All metadata in HGL adheres to the Federal Geographic Data Committee Content Standard for Geospatial Metadata.
peters.hul.harvard.edu:8080/HGL/html/Help/glossary.htm
Metadata is a description or definition of electronic data, or data about data. Often, metadata can only be accessed in certain viewing modes. Metadata can include descriptive HTML tags (see Meta Tag) and information about when a document was created, and what changes have been made on that document.
practice.findlaw.com/glossary.html
Information about data set. Metadata for geographical data may include the source of the data; its creation date and format; its projection, scale, resolution, and accuracy; and its reliability with regards to some standard. See data dictionary.
www.richlandmaps.com/training/glossary/m_p.html
Data that describe a dataset to allow others to find and evaluate it.
hds.essex.ac.uk/g2gp/gis/sect101.asp
Data about data. How the structures and calculation rules are stored, plus, possibly, additional information on data sources, definitions, quality, transformations, date of last update, user access privileges, etc.
www.olapreport.com/glossary.htm
A set of information that fully describes each data file in the archive. Metadata stored in the KOA database includes: FITS header keyword values (both those written by the telescope, and those added by the archive processing software); file location information; spatial coordinates and spatial bin assignments; proprietary period information; and certain transformations of original FITS keyword values (for instance, RA and DEC are stored as decimal values; the original FITS sexagesimal ...
koa.ipac.caltech.edu/deepimpact/glossary.html
Metadata is the structured description of an object or collection of objects and is similar to what is found in a standard cataloging record. There are three kinds of metadata:
www.law.harvard.edu/library/collections/digital/guidelines_glossary.php
A description of data.
www.epa.gov/cdx/about/glossary.htm
data about data; "a library catalog is metadata because it describes publications"
wordnet.princeton.edu/perl/webwn
Metadata (Greek: meta-+data "information") means data about data. While this definition is commonly offered, it is also commonly not helpful. An example is a library catalog card, which contains data about the nature and location of a book: It is data about the data in the book referred to by the card.
en.wikipedia.org/wiki/Metadata
Metadata is the name of a US corporation and a registered trademark in the United States.
en.wikipedia.org/wiki/Metadata_(corporation)

What’s metadata? What’s a data dictionary?

2009-06-25T23:10:00.000-07:00

Metadata is data about data. Metadata gives you data element definitions, data layouts, and information about the data element’s location. Data elements are the smallest unit of data that can be described, for example the zip code field within an address database record. The University’s data warehouse refers to their metadata as data dictionaries. You can access the data dictionaries on the IDEA web page . Click on the Information button, then click on the Data Element Dictionary for the database of your choice.

Definitions of electronic data exchange on the Web:

2009-06-25T02:20:00.000-07:00

An international standard for the exchange of debit and credit transactions, such as bank debts, commercial invoices and purchase orders.
www.btinternet.com/~mbohan/phantasy/jargone.htm

fīr´wâl) (n.) A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

There are several types of firewall techniques:

· Packet filter: Looks at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.

· Application gateway: Applies security mechanisms to specific applications, such as FTP and Telnet servers. This is very effective, but can impose a performance degradation.

· Circuit-level gateway: Applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking.

· Proxy server: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.

In practice, many firewalls use two or more of these techniques in concert.

A firewall is considered a first line of defense in protecting private information. For greater security, data can be encrypted.

Definitions of software agent on the Web:

2009-06-24T02:19:00.000-07:00

A software program that intelligently performs its duties without human inter-action.
docs.rinet.ru/Plugi/appc.htm
In computer science, a software agent is a piece of autonomous, or semi-autonomous proactive and reactive, computer software. Many individual communicative software agents may form a multi-agent system.
en.wikipedia.org/wiki/Software_agent

Definitions of public key certificate on the Web:

2009-06-23T02:19:00.000-07:00

A digital certificate that binds unforgeably the public key of an entity to the entity's distinguishing identifier, and which indicates the validity of the corresponding private key. [ISO/IEC 13888-1: 1997]
www.ecommercepki.com/cps/glossary.htm
Public key and identification data signed by a trusted third party to provide authentication and integrity of the key.
www.maithean.com/products/glossary.html
In cryptography, a public key certificate (or identity certificate) is a certificate which uses a digital signature to bind together a public key with an identity — information such as the name of a person or an organisation, their address, and so forth. The certificate can be used to verify that a public key belongs to an individual.
en.wikipedia.org/wiki/Public_key_certificate

Definitions of negotiation on the Web:

2009-06-22T02:18:00.000-07:00

a discussion intended to produce an agreement; "the buyout negotiation lasted several days"; "they disagreed but kept an open dialogue"; "talks between Israelis and Palestinians"
the activity or business of negotiating an agreement; coming to terms
wordnet.princeton.edu/perl/webwn
Negotiation is the process whereby interested parties resolve disputes, agree upon courses of action, bargain for individual or collective advantage, and/or attempt to craft outcomes which serve their mutual interests. It is usually regarded as a form of alternative dispute resolution.
en.wikipedia.org/wiki/Negotiation
This method is often used when selling real estate. Federal agencies may negotiate individual property sales as a way to sell the property. At other times, negotiation may be used in special circumstances. For example, GSA may negotiate a sale if, after advertising, the bid prices are not reasonable or if the specialized property is of interest only to a small group of buyers. ...
www.pueblo.gsa.gov/cic_text/fed_prog/fedsales/glossary.htm
The act of discussing an issue between two or more parties with competing interests with an aim of coming to an agreement.
www.realestateagent-listings.com/terminology/terminology_n.htm
Make an offer and we will attempt to negotiate a concluded contract between the parties.
www.reinz.org.nz/reinz/public/buyers-sellers/terminology.cfm
Discussion, written or otherwise, between two or more parties of different sides, the aim being to reach a common agreement.
narains.com/glossary.htm
The face to face process used by local unions and the employer to exchange their views on those matters involving personnel policies and practices or other matters affecting the working conditions of employees in the unit and reduced to a written binding agreement. Used also by contracting officers to reach agreement with potential contractors.
www.business.gov/phases/launching/are_you_ready/glossary.html
Discussion, written or otherwise, between two or more parties no different sides, the aim being to reach a common agreement. Non-confirming use: The use of a property, which does not conform to the allocation of the area for planning purposes. Such a property may have been built in conformity with the planning requirement at the time and a policy change ensued; more usually, the property was constructed before planning control was introduced. ...
www.amchegoa.com/real_estate_goa/glossary1.htm
the process of two or more people working together to resolve a problem.
www.nationaltcc.org/tcc/
Requests for proposals are sometimes used as a starting point for negotiations to establish a contract. RFPs generally include more than just price considerations. This method is especially applicable when dealing with a single source manufacturer.
www.mmd.admin.state.mn.us/mn06008.htm
a discussion with the aim of resolving a difference of opinion, or dispute, or to settle the terms of an agreement or transaction.
www.powerhomebiz.com/Glossary/glossary-N.htm
A dispute resolution process in which two parties settle their differences by themselves, without the use of a third-party.
www.cfson-crcsf.ca/en/glossary/
to confer with another so as to arrive at the settlement of some matter through conference, discussion, and compromise.
www.inspection.gc.ca/english/corpaffr/publications/riscomm/riscomm_appe.shtml
the use of direct argument and compromise by the parties to a dispute to arrive at a mutually satisfactory agreement.
oregonstate.edu/instruct/anth370/gloss.html
Contracting through the use of either competitive or other-than-competitive proposals and discussions. Any contract awarded without using sealed bidding procedures is a negotiated contract.
strategicsourcing.navy.mil/reference_documents/defs.cfm
A process of communication by which parties attempt to resolve a dispute between them.
www.mediate.ca/shortglossary.htm
The bargaining process between a buyer and a seller.
www.horizonmedia.com/glossary/n.htm
In dispute settlement, this is discussion designed to reach a mutual agreement.
www.attorneykennugent.com/library/n.html
The transaction of business aimed at reaching a meeting of minds among the parties; bargaining.
www.bthurston.com/Real_Estate_Dictionary/page_644889.html
In X.25 communications, the process by which two DTEs establish the packet size, packet window size, and throughput class to be used during a call procedure. Contrast with validation.
www.ncsa.uiuc.edu/UserInfo/Resources/Hardware/IBMp690/IBM/usr/share/man/info/en_US/a_doc_lib/aixuser/glossary/N.htm
A two-way process whereby the owner through the services rendered by the architect contests the offer made by the contractor to obtain more favorable terms that better match the proposed construction intent and the owner’s budget.
www.ordesignandconstruction.com/glossary.htm
Parties involved in the dispute discuss options for resolution without the help of a third party.
www.commongroundinc.org/terminology.htm
The art of achieving what you want from a transaction, leaving all other parties involved content that the relationship has gone well.
www.mccombs.utexas.edu/faculty/Linda.Bailey/glossary.htm
Communication, often between the party’s attorneys, for the purpose of reaching an understanding.
www5.aaos.org/oko/vb/online_pubs/professional_liability/glossary.cfm
A technological style dominant from 1600 to about 1880. Characterized by flexibility and compromise.
www.udmercy.edu/faculty_pages/staudenmaier_sj/ethics/glossary.html
The process of bargaining that precedes an agreement.
www.peakagents.ca/glossary/n2.htm

Definitions of mIS on the Web:

2009-06-21T02:18:00.000-07:00

MIS is a TLA that can stand for:* Management Information Systems* Mercalli Intensity Scale of earthquakes* Minimally invasive surgery* Michigan International Speedway* Mississippi Central Railroad * Metal-Insulator Semiconductor
en.wikipedia.org/wiki/MIS
Teddy Bear is the English title of Miś, a 1980 Polish film directed by Stanisław Bareja.
en.wikipedia.org/wiki/Mis
Management information system.
www.epa.gov/records/gloss/gloss00.htm
Produced by the Sertoli cells, and inhibits Mullerian duct formation
www.hopkinschildrens.org/specialties/categorypages/intersex/sd9.html
Management Information Systems.
www.krollontrack.co.uk/legalresources/glossary.asp
Major Investment Study
www.tzbsite.com/glossary/
Mandated by federal law, a Major Investment Study (MIS) is a study that examines transportation improvements for a corridor and determines the feasible alternatives. It allows local officials and citizens to participate in the planning process and helps to make sure all alternatives are carefully considered. COTA submitted its first MIS for the NCLRT Project in 1995.
www.cotafasttrax.com/glossary/glossary.php
A general term for the computer systems in an organisation hat provide information about its business operations. It's also used to refer to the people who manage these systems. Typically, in a large corporation, "MIS" or the "MIS department" refers to a central or centrally-coordinated system of computer expertise and management, often including mainframe systems but also including by extension the corporation's entire network of computer resources.
www.stanlake.co.uk/recruitment-candidates/recruitment-glossary.php
Major Investment Study A study that reviews and evaluates a range of alternatives for proposed transportation improvements in a corridor or subarea.
www.njtpa.org/capital_programming/glossary.htm
detailed study and assessment of the various options available for the purpose of selecting one for implementation.
managed-lanes.tamu.edu/products/glossary.stm
A wildlife species whose population will indicate the health of the ecosystem in which it lives and, consequently, the effects of forest management activities to that ecosystem. MIS species are selected by land management agencies. (See "indicator species".)
www.umpqua-watersheds.org/glossary/gloss_m.html
1. An organized approach to gathering data from inside and outside the company and processing it by computer to produce current, accurate, and informative reports for decision makers; 2. A system that provides management with needed information on a regular basis.
www.crfonline.org/orc/glossary/m.html
An indicator species designated in the Carson National Forest Plan to represent other groups of species.
www.fs.fed.us/r3/carson/plans/ojo_caliente/html/glossary.html
database developed by APACS to record and analyse data from UK payments industry. manual reversal: reversal of a transaction effected by manual entry of data and often off line processing.
www.gbc.t-online.hu/english/bszotare3.htm
"Management of Information Services" MIS is the designation for the field of computer solutions internal to an organisation. An MIS department is typically responsible for administering the computer hardware, software, and networking within a company or group.
www.scotsmist.co.uk/glossary_m.html
This stands for Management Information Systems, and is really just another name for data processing.
www.satellite-tv-hq.com/telecom-glossary-m.htm
Information systems designed for structured flow of information and integrating EDP jobs by business functions and generating reports from a database.
home.att.net/~c-and-d/Definitions.htm
A computer system that presents high level summary information that assists management decision making.
www.gov.bc.ca/prem/popt/service_plans/srv_pln/pssg/appen_a.htm
Management information systems that are associated with ACD systems can provide information about calls, agents and agent groups. This information is used for preparation of statistical reports. The MIS also has current information, eg number of calls on the queue, which agents are in wrap-up time or the total number of calls answered in that day.
www.flexiblelearning.net.au/toolbox/demosites/series3/317/resources/glossary/gls_idx.htm
Mortgage Information System.
www.gloriabryant.com/glossary.aspx
marketing information system; the formalised collection, sorting, analysis, evaluation, storage and distribution of marketing data.
wps.pearsoned.co.uk/wps/media/objects/1452/1487687/glossary/glossary.html
This is the computer mainframe used for company transactions.
totalqualityassurance.net/
Management Information Systems. Systems that capture the essence of management controls through concise formats.
ravi.freeshell.org/rsg/ch10.htm

Definitions of digital signature on the Web:

2009-06-20T02:17:00.000-07:00

Information that is encrypted with an entity private key and is appended to a message to assure the recipient of the authenticity and integrity of the message. The digital signature proves that the message was signed by the entity that owns, or has access to, the private key or shared secret symmetric key.
www.sabc.co.za/manual/ibm/9agloss.htm
A digital signature is like a paper signature, but it is electronic. A digital signature cannot be forged. A digital signature provides verification to the recipient that the file came from the person who sent it, and it has not been altered since it was signed.
sig.nfc.usda.gov/pki/glossary/glossary.html
A digital signature is an electronic rather than a written signature that can be used by someone to authenticate the identity of the sender of a message or of the signer of a document. It can also be used to ensure that the original content of the message or document that has been conveyed is unchanged.
www.creotec.com/index.php
A way to ensure whether a message was actually sent by the person who claimed to have sent it. The sender's private key encrypts the signature, and the recipient decrypts the signature with the sender's public key. Digital signatures use public key cryptography and work in conjunction with certificates
www.vpsource.com/glossary.html
A block of data attached to a message that serves to "digitally sign" the message; it is transmitted along with the message to a recipient. The purpose of the digital signature is to identify the sender, verify the message has not been altered in transit, and provide support for nonrepudiation. It is a two-step cryptographic process: first, the message to be transmitted undergoes a hash algorithm (for example, SHA-1) to obtain a message digest (or hash value). ...
www.sequi.com/SEQUI_VPN_Glossary.htm
systems allow people and organizations to electronically certify such features as their identity, their ability to pay, or the authenticity of an electronic document.
www.ciphers.de/products/glossary.html
A cryptographic code consisting of a hash, to indicate that data has not changed, that can be decrypted with the public key of the creator of the signature.
www.cs.cornell.edu/wya/DigLib/MS1999/glossary.html
The result of a transformation of a message by means of a cryptographic system using keys such that a Relying Party can determine: 1. whether the transformation was created using the private key that corresponds to the public key in the signer's digital certificate; and 2. whether the message has been altered since the signature creation.
www.certification.tn/Conference/PKITunisia2005/Glossary.htm
An electronic signature based upon cryptographic methods of originator authentication, computed by using a set of rules and a set of parameters such that the identity of the signer and the integrity of the data can be verified.
www.data-core.com/glossary-of-terms.htm
An electronic signature that is impossible to forge. Instead, the digital signature comes from a digest of the text encrypted and sent with the text message. The recipient decrypts the signature and retrieves the digest from the received text. A match authenticates the message.
www.freecreditcardprocessing.com/html/glossary.html
An encrypted message digest which is appended to a plaintext or encrypted message to verify the identity of the sender. The signature is encrypted with the user's private key and can only be decrypted with the corresponding public key. The same key pairs may be used for signature and encryption purposes but separate key pairs for each purpose are usually recommended.
www.efa.org.au/Issues/Crypto/crypto5.html
A use of public key cryptography to authenticate a message. The private key is used, showing that the signature must have been made by the owner of that key. A secure hash of the entire document is signed, so that any change to the document will invalidate the signature.
survey.netcraft.com/surveys/analysis/https/2004/Jan/glossary.html
An electronic version of a traditional signature that can be used as a means of identifying and authenticating documents sent and received electronically.
www.epa.gov/cdx/about/glossary.htm
The origin of data can be proved by means of a digital signature. The term describes electronic signatures that are generated and verified using asymmetric encryption. ...
www.secardeo.com/Solutions/Glossary/glossary.html
A structure of binding a principal’s identity to it’s public key. A certification authority (CA) issues and digitally signs a digital signature.
www.mynetsec.com/html/security.htm
A data string which associates a message (in digital form) with some originating entity. A cryptographic primitive which is fundamental in authentication, authorization and non-repudiation is the digital signature. The purpose of a digital signature is to provide a means for an entity to bind its identity to a piece of information. The process of signing entails transforming the message and some secret information held by the entity into a tag called a signature.
www.wetstonetech.com/page/page/1972572.htm
An electronic signature that authenticates the identity of the sender, ensures the original content of the message is unchanged, is easily transportable, cannot be easily repudiated, cannot be imitated, and can be automatically time-stamped
www.techarch.state.ar.us/domains/security/overview/glossary.htm
Any type of text or message, encrypted with a private key, thereby identifying the source.
www.cafesoft.com/support/security-glossary.html
The result of encrypting a hash of a message or document with a private key. A digital signature is used to verify the authenticity of the sender and the integrity (unaltered condition) of the message or document. See also hash.
www.trapezenetworks.com/technology/glossary_1.asp
The password entered during the approval process. The Digital signature verifies that a specific user has created or approved an electronic document and that the document has not been altered since it was signed.
www.tradecard.com/resources/supplychain.html
Piece of data sent with an encoded message to uniquely identify the originator and verify the message has not been altered after sending.
www.merchant-in-a-box.com/glossary.htm
A means of authenticating the identity of the sender of a digital message and proving the integrity of the message by means of the data appended to that message
www.cordis.lu/ist/ka1/administrations/publications/glossary.htm
A Digital Signature is a mark (in digital form) that only the sender of an electronic transmission can make but which is easily recognised as belonging to the sender.
www.its.monash.edu.au/security/certs/theory/pki_definitions.html
A section of data appended to a message which authenticates the information. Signatures are encoded by the sender's private key and can then verified by the sender's public key. Any unauthorised changes to the file will be reported by an invalid signature for that file.
www.wiredmedia.co.uk/docs/120.html
The result of a cryptographic transformation of data which, when properly implemented, and used within a complete infrastructure provides the services of: 1. origin authentication, 2. data integrity, and 3. signer non-repudiation.
www.ca0.net/Glossary.html
Digital signatures are a method of authenticating digital information analogous to ordinary physical signatures on paper, but implemented using techniques from the field of cryptography. Digital signatures differ in some respects from their physical counterparts, however.
en.wikipedia.org/wiki/Digital_signature