My query takes 30+ minutes to process this query. It indeed works on very large data set, however I may be missing something basic which can reduce the execution time.
Query works on many reducer stages each using 1000+ reducers. Runs on Tez engine.
I tried to enable CBO but no luck, also tried to limit reducers to 500 but execution time remains high.
select itt.tr_date, sum (bkt_sum_pc) as pts
from itops_trxn itt,
( select acttrxnID, max(act_cmp_id) as act_cmp_id
from itops_trxn_act a, ll_act_act_trxn b where a.act_trxn_ID = b.ACOUNTtrxnID group by acttrxnID
) A,
(select cmp_id, max (cmp_name) as name
from itops_offer group by cmp_id
) c
where itt.acttrxnID = A.acttrxnID and act_cmp_id = c.cmp_id
and itt.type = 'ajstmnt'
and itt.event_header_event_name NOT IN ('composite.sys.act.merge', 'pos.sys.identity', 'composite.sys.act.pcmerge')
and itt.event_atomic_operation_type = 'CT'
and itt.tr_date >='2018-10-31'
group by itt.tr_date, channel, location_storeparentid, meta_trxnreason, act_cmp_id,name;
Rewrite joins explicitly and move these conditions
where itt.acttrxnID = A.acttrxnID and act_cmp_id = c.cmp_id
to the join ON clause:
select itt.tr_date, sum (bkt_sum_pc) as pts
from itops_trxn itt
INNER JOIN
( select acttrxnID, max(act_cmp_id) as act_cmp_id
from itops_trxn_act a, ll_act_act_trxn b where a.act_trxn_ID = b.ACOUNTtrxnID group by acttrxnID
) A ON itt.acttrxnID = A.acttrxnID
INNER JOIN
(select cmp_id, max (cmp_name) as name
from itops_offer group by cmp_id
) c ON A.act_cmp_id = c.cmp_id
where itt.type = 'ajstmnt'
and itt.event_header_event_name NOT IN ('composite.sys.act.merge', 'pos.sys.identity', 'composite.sys.act.pcmerge')
and itt.event_atomic_operation_type = 'CT'
and itt.tr_date >='2018-10-31'
group by itt.tr_date, channel, location_storeparentid, meta_trxnreason, act_cmp_id,name;