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Can somebody help me avoid nested loops in below query: -- ap_poc_db=# explain (analyze,buffers) ap_poc_db-# select site_id, account_id FROM ap.site_exposure se ap_poc_db-# WHERE se.portfolio_id=-1191836 ap_poc_db-# AND EXISTS (select 1 from ap.catevent_flood_sc_split sp where sp.migration_sourcename= 'KatRisk_SC_Flood_2015_v9' AND ST_Intersects(se.shape, sp.shape)) ap_poc_db-# group by site_id, account_id; QUERY PLAN -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Group (cost=23479854.04..23479880.06 rows=206 width=16) (actual time=1387.825..1389.134 rows=1532 loops=1) Group Key: se.site_id, se.account_id Buffers: shared hit=172041 -> Gather Merge (cost=23479854.04..23479879.04 rows=205 width=16) (actual time=1387.823..1388.676 rows=1532 loops=1) Workers Planned: 5 Workers Launched: 5 Buffers: shared hit=172041 -> Group (cost=23478853.96..23478854.27 rows=41 width=16) (actual time=1346.044..1346.176 rows=255 loops=6) Group Key: se.site_id, se.account_id Buffers: shared hit=864280 -> Sort (cost=23478853.96..23478854.07 rows=41 width=16) (actual time=1346.041..1346.079 rows=255 loops=6) Sort Key: se.site_id, se.account_id Sort Method: quicksort Memory: 37kB Buffers: shared hit=864280 -> Nested Loop Semi Join (cost=4.53..23478852.87 rows=41 width=16) (actual time=34.772..1345.489 rows=255 loops=6) Buffers: shared hit=864235 -> Append (cost=0.00..156424.56 rows=123645 width=48) (actual time=1.011..204.748 rows=102990 loops=6) Buffers: shared hit=154879 -> Parallel Seq Scan on site_exposure_1191836 se (cost=0.00..156424.56 rows=123645 width=48) (actual time=1.004..187.702 rows=102990 loops=6) Filter: (portfolio_id = '-1191836'::integer) Buffers: shared hit=154879 -> Bitmap Heap Scan on catevent_flood_sc_split sp (cost=4.53..188.54 rows=15 width=492) (actual time=0.007..0.007 rows=0 loops=617937) Recheck Cond: (se.shape && shape) Filter: ((migration_sourcename = 'KatRisk_SC_Flood_2015_v9'::bpchar) AND _st_intersects(se.shape, shape)) Rows Removed by Filter: 0 Heap Blocks: exact=1060 Buffers: shared hit=709356 -> Bitmap Index Scan on catevent_flood_sc_split_shape_mig_src_gix (cost=0.00..4.52 rows=45 width=0) (actual time=0.005..0.005 rows=0 loops=617937) Index Cond: (se.shape && shape) Buffers: shared hit=691115 Planning time: 116.141 ms Execution time: 1391.785 ms (32 rows) ap_poc_db=# Thank you in advance! Regards, Virendra This message is intended only for the use of the addressee and may contain information that is PRIVILEGED AND CONFIDENTIAL. If you are not the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please erase all copies of the message and its attachments and notify the sender immediately. Thank you. |
