Hi,
What is the meaning of 'materializing' a relation after sequential scan?
explain select * from tb1, tb2 where tb1.c1 = tb2.c2;
QUERY PLAN
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Nested Loop (cost=1.03..2.34 rows=3 width=24)
Join Filter: (tb1.c1 = tb2.c1)
-> Seq Scan on tb2 (cost=0.00..1.04 rows=4 width=12)
-> Materialize (cost=1.03..1.06 rows=3 width=12)
-> Seq Scan on tb1 (cost=0.00..1.03 rows=3 width=12)
In this above plan, what does 'Material' mean?
Thanks,
Rupesh