What are Dimensions and various types of Dimensions?
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Answer / vvm.sp
Subject of the mesurable data. Dimensions are mainly 11
types. They are
1. Changing Dimension
2. Slowly Changing Dimension
3. Rapidly Changing Dimension
4. Conformed Dimension
5. Degenerate Dimension
6. Junk Dimension
7. Inferred Dimension
8. Role Playing Dimension
9. Shrunken Dimension
10. Out Triggers
11. Static Dimension
| Is This Answer Correct ? | 46 Yes | 13 No |
Answer / atul
Type of Dimension
Conformed Dimension
Dimensions are conformed when they are either exactly the
same (including keys) or one is a perfect subset of the
other. Most important, the row headers produced in the
answer sets from two different conformed dimensions must be
able to match perfectly.
Conformed dimensions are either identical or strict
mathematical subsets of the most granular, detailed
dimension. Dimension tables are not conformed if the
attributes are labeled differently or contain different
values. Conformed dimensions come in several different
flavors. At the most basic level, conformed dimensions mean
the exact same thing with every possible fact table to
which they are joined. The date dimension table connected
to the sales facts is identical to the date dimension
connected to the inventory facts.[1]
Junk Dimension
A junk dimension is a convenient grouping of typically low-
cardinality flags and indicators. By creating an abstract
dimension, these flags and indicators are removed from the
fact table while placing them into a useful dimensional
framework.[2]
Degenerated Dimension
A dimension key, such as a transaction number, invoice
number, ticket number, or bill-of-lading number, that has
no attributes and hence does not join to an actual
dimension table. Degenerate dimensions are very common when
the grain of a fact table represents a single transaction
item or line item because the degenerate dimension
represents the unique identifier of the parent. Degenerate
dimensions often play an integral role in the fact table's
primary key.[3]
Role-Playing Dimensions
Dimensions are often recycled for multiple applications
within the same database. For instance, a "Date" dimension
can be used for "Date of Sale", as well as "Date of
Delivery", or "Date of Hire". This is often referred to as
a "role-playing dimension".
| Is This Answer Correct ? | 27 Yes | 9 No |
Answer / shashiall
Dimensions contains Textual attributes.
It is Wide not Deep.(whereas FACT is deep not wide)
about Dimensions..
The Slowly Changing Dimensions Wizard creates mappings to
load slowly changing dimension tables:
Type 1 Dimension mapping. Loads a slowly changing dimension
table by inserting new dimensions and overwriting existing
dimensions. Use this mapping when you do not want a history
of previous dimension data.
Type 2 Dimension/Version Data mapping. Loads a slowly
changing dimension table by inserting new and changed
dimensions using a version number and incremented primary
key to track changes. Use this mapping when you want to
keep a full history of dimension data and to track the
progression of changes.
Type 2 Dimension/Flag Current mapping. Loads a slowly
changing dimension table by inserting new and changed
dimensions using a flag to mark current dimension data and
an incremented primary key to track changes. Use this
mapping when you want to keep a full history of dimension
data, tracking the progression of changes while flagging
only the current dimension.
Type 2 Dimension/Effective Date Range mapping. Loads a
slowly changing dimension table by inserting new and
changed dimensions using a date range to define current
dimension data. Use this mapping when you want to keep a
full history of dimension data, tracking changes with an
exact effective date range.
Type 3 Dimension mapping. Loads a slowly changing dimension
table by inserting new dimensions and updating values in
existing dimensions. Use this mapping when you want to keep
the current and previous dimension values in your dimension
table.
apart from these: there are...
Confirmed dimensions
Junk Dimensions
Degenerated dimension
Thanks...
| Is This Answer Correct ? | 20 Yes | 7 No |
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