SELECT block_timestamp as bt , block_number as bn from polygon.core.fact_blocks),

poly as

( SELECT date(block_timestamp) as day, avg(td) as avg_time_taken,

avg(avg_time_taken) over (order by day) as avg_time_taken_over_time , 'polygon' as type

from

( SELECT *

, timestampdiff(sql_tsi_second,bt, block_timestamp) as td

from p

inner join polygon.core.fact_blocks

on block_number = bn +1 )

where day>= CURRENT_DATE -90

GROUP by 1 )

SELECT * from poly

limit 100