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Data Science & Analytics vocabulary · SQL and Querying

Window function

Meaning in data science & analytics, with examples

nounAdvanced term

In data science & analytics, window function means: A SQL function that calculates a value across a set of rows related to the current row, such as a running total or a rank, without merging those rows into one.

In Turkish: pencere fonksiyonu, window function

How it is used

Written with OVER, often together with PARTITION BY and ORDER BY. Common examples are ROW_NUMBER, RANK, LAG, LEAD and moving averages. A favourite topic in SQL interviews for analyst jobs.

Example sentences

  1. Use a window function with LAG to compare each month with the previous one.

  2. I used a window function to rank products by sales within each category.

Common collocations

  • running total
  • PARTITION BY
  • rank within a group
  • moving average
  • SQLShort for Structured Query Language: the standard language for reading, filtering, combining and changing data stored in relational databases and data warehouses.
  • CTEShort for common table expression: a temporary, named result defined with WITH at the start of a SQL query, which makes long queries easier to read.
  • aggregateTo combine many rows of data into summary values, such as totals, counts or averages, usually grouped by a category such as day, product or region.
  • queryA request for specific data from a database, usually written in SQL; as a verb, to ask a database or dataset for that data.

This word in other fields

The same English word can have a different meaning in another field:

More terms: SQL and Querying

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