---------------------------------------------------------------------------------------------------------------------------------------------------
select id, count(date) as
cnt from t2006 group by id
---------------------------------------------------------------------------------------------------------------------------------------------------
Aggregate
(cost=2456925.41..2504597.16 rows=635623 width=76)
-> Group (cost=2456925.41..2488706.58 rows=6356233
width=76)
-> Sort (cost=2456925.41..2472816.00 rows=6356233
width=76)
Sort Key: id
-> Seq Scan on t2006 (cost=0.00..194859.33
rows=6356233 width=76)
--------------------------------------------------------------------------------------------------------------------------------------------------- id : character varying(100)
date : timestamp with time zone
---------------------------------------------------------------------------------------------------------------------------------------------------
t2006
테이블의 데이타 갯수 : 6,356,233
---------------------------------------------------------------------------------------------------------------------------------------------------
날짜 조건을 뺐습니다.. 속도를 줄일려면 어떻게 하면 좋을까요?
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