How to Get the Size of Filtered Rows in Databricks SQL

[vidya_kothavale]

I have a query that filters rows from a table based on a timestamp range. The query is as follows:

SELECT COUNT(*) FROM table_name WHERE ts >= '2025-02-04 00:00:00' AND ts < '2025-02-05 00:00:00';

This query returns 10 rows. I need to calculate the total size (in bytes) of these 10 rows.

What is the best approach in Databricks SQL to get the exact size of these filtered rows?
is there a built-in function to get this information?

[holly]

You'd have to write the results to a table, then do 

DESCRIBE DETAIL table_name

and look for the column sizeInBytes

[MadhuB]

@vidya_kothavale try this code block. Keep in mind to handle the null values.

SELECT 
    SUM(OCTET_LENGTH(CAST(column1 AS STRING)) + OCTET_LENGTH(CAST(column2 AS STRING)) + OCTET_LENGTH(CAST(COALESCE(column3, '0') AS STRING))) as bytes,
    SUM(OCTET_LENGTH(CAST(column1 AS STRING)) + OCTET_LENGTH(CAST(column2 AS STRING)) + OCTET_LENGTH(CAST(COALESCE(column3, '0') AS STRING))) /POWER(1024,2) as mb,
    SUM(OCTET_LENGTH(CAST(column1 AS STRING)) + OCTET_LENGTH(CAST(column2 AS STRING)) + OCTET_LENGTH(CAST(COALESCE(column3, '0') AS STRING))) /POWER(1024,3) as gb 
FROM catalog.schema.table where ts >= '2025-02-04 00:00:00' AND ts < '2025-02-05 00:00:00';

Let me know for anything, else mark it as solution.