Table of Contents

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  1. Preface
  2. Introduction to Informatica Big Data Management
  3. Mappings
  4. Sources
  5. Targets
  6. Transformations
  7. Data Preview
  8. Cluster Workflows
  9. Profiles
  10. Monitoring
  11. Hierarchical Data Processing
  12. Hierarchical Data Processing Configuration
  13. Hierarchical Data Processing with Schema Changes
  14. Intelligent Structure Models
  15. Stateful Computing
  16. Connections
  17. Data Type Reference
  18. Function Reference

Frame

Frame

The frame determines which rows are included in the calculation for the current input row, based on their relative position to the current row.
If you use an aggregate function instead of LEAD or LAG, you must specify a window frame. LEAD and LAG reference individual row sand ignore the frame specification.
The start offset and end offset describe the number of rows that appear before and after the current input row. An offset of "0" represents the current input row. For example, a start offset of -3 and an end offset of 0 describes a frame including the current input row and the three rows before the current row.
The following image shows a frame with a start offset of -1 and an end offset of 1:
The table has five rows. The middle row is the current input row, and the frame includes one row before the current row and one row after the current row.
For every input row, the function performs an aggregate operation on the rows inside the frame. If you configure an aggregate expression like SUM with the preceding frame, the expression calculates the sum of the values within the frame and returns a value of 6000 for the input row.
You can also specify a frame that does not include the current input row. For example, a start offset of 10 and an end offset of 15 describes a frame that includes six total rows, from the tenth to the fifteenth row after the current row.
The start offset must be less than or equal to the end offset.
Offsets of
All Rows Preceding
and
All Rows Following
represent the first row of the partition and the last row of the partition. For example, if the start offset is All Rows Preceding and the end offset is -1, the frame includes one row before the current row and all rows before that.
The following figure illustrates a frame with a start offset of 0 and an end offset of All Rows Following:
The frame includes the current input row and all rows below the current input row.


Updated January 20, 2020