I've read query plans in SQL Server forever using a GUI, but text plans are like Greek to me (I don't speak Greek). I'm trying to figure out if statements like this calculate the date "constant" for each row and cause performance lag, or if Impala knows to calculate it once and apply to all rows. select *
from myTable
-- the "months_add" is basically a constant, but I can see
-- why a function might be calculated for each row
where tran_timestamp > months_add(now(), -1)
limit 1;
select *
from myTable
-- but what about this? this is definitely a constant
-- so is this different than the query above and is
-- the "constant" calculated for each row?
where tran_timestamp > months_add('2021-01-01', -1)
limit 1
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