Search Ctrl K
Home / Tools
THE FEUTEX TOOLKIT

Column Projection Scan Reduction

Compare row reads with selected columns when columns have equal encoded width.

Computer Systems workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
FormulaRow layout payload read = rows*cols*width/1e9; Projected column payload read = rows*select*width/1e9

Made for real tasks

  • Compare row reads with selected columns when columns have equal encoded width.
Explore step-by-step workflows →

Worked example

Inputs

Rows scanned
10000000 rows
Total columns
40 columns
Selected columns
3 columns
Bytes per cell
8 bytes

Expected results

Row layout payload read
3.2 GB
Projected column payload read
0.24 GB

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter rows scanned, total columns, selected columns, bytes per cell in the displayed units.
  2. Calculate the scenario, then compare it with measurements before changing a system.

Try this example

{
  "rows": 10000000,
  "cols": 40,
  "select": 3,
  "width": 8
}

Accuracy and scope

Equal encoded widths; compression, indexes, predicates, headers and caching excluded.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.