Rank Transformation
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Transcript of Rank Transformation
Informatica Training- Day 5Rank Transformation
Course Objective
• To introduce the basic concept of Rank Transformation
• To familiarize with the components and features of Rank Transformation
Session Plan
Rank Transformation - Purpose
Rank Transformation - Overview
Rank Transformation – Ranking String Values
Rank Transformation - Ports
Rank Transformation - Properties
Rank Transformation - Application
References
• Informatica Manuals: Installation and Configuration Guide
Rank Transformation - Purpose
Allows you to select only the top or bottom rank of data
Returns the largest or smallest numeric value in a port or group
Returns the strings at the top or the bottom of a session sort order
Differs from transformation functions MAX and MIN, in that it allows you to select a group of top or bottom values, not just one value
Rank Transformation - Overview
Rank Transformation is an Active & Connected Transformation
Connects ports from only one transformation to Rank transformation
Supports groups, creates one set of ranked rows for each group Can designate one input/output group as Group By Port
Rank Transformation has following components Ranking String Values Rank Ports
Rank Transformation – Ranking String Values
Ranking String Values
Defines Sort Order based on Data Code Movement
For ASCII mode, it sorts session data using a binary sort order
For Unicode mode, Server uses sort order configured for the session
Rank Transformation - Ports.
Ports Number Required Description
I Minimum of 1 Input port
O Minimum of 1 Output port . Can be an input port also
V Not Required Variable port
R One only Rank port. It is an Input/Output port
Rank Ports
Can be any input, input/output, output, variable and a rank port
Rank Transformation - Ports.
Rank Port
Use to designate the column for which you want to rank values
You must link the Rank port to another transformation
Rank Index
Designer automatically creates a RANKINDEX port for each Rank transformation
Server uses this port to store the ranking position for each row in a group
RANKINDEX is an output port only
Filters the top or bottom range of records
Rank Transformation - Ports
Can be added in the mapping anywhere after source qualifier.
PortsRank IndexRank Port
Rank Transformation - Properties
Top/Bottom
Specifies whether you want the top or bottom ranking for a column
Number of Ranks
Number of rows you want to rank
Case-Sensitive String Comparison
If session sort order is case-sensitive, select this to enable case-sensitive string comparisons, and clear this to ignore case for strings
Rank Transformation - Properties
Rank Cache
In a session, Server compares an input row with data cached rows. If input row out-ranks a cached row, Server replaces cached row with the input row
Server stores group information in an index cache and row data in a data cache
If Rank transformation is configured to rank across multiple groups, Server ranks incrementally for each group it finds
Rank Transformation - Properties.
Used when we need to find the upper or lower values as a group, rather than a single value.
Application
Summary
Rank Transformation Purpose
Rank Transformation Overview
Rank Transformation Ranking String Values
Rank Transformation Ports
Rank Transformation Properties
Application