The MIN_DATA_RETENTION_TIME_IN_DAYS parameter is set at the account level. This parameter determines the minimum number of days Snowflake retains historical data for Time Travel operations

https://medium.com/@divyanshsaxenaofficial/snowflake-loading-unloading-of-data-part-1-internal-stages-7121cc3cc9

To convert semi-structured data into rows and columns in Snowflake, the FLATTEN function is utilized.
FLATTEN Function: This function takes semi-structured data (e.g., JSON) and transforms it into a relational table format by breaking down nested structures into individual rows. This process is essential for querying and analyzing semi-structured data using standard SQL operations.
Example Usage:
SELECT
f.value:attribute1 AS attribute1,
f.value:attribute2 AS attribute2
FROM
my_table,
LATERAL FLATTEN(input => my_table.semi_structured_column) f;
Reference:
Snowflake Documentation on FLATTEN