explain.depesz.com

PostgreSQL's explain analyze made readable

Result: 8X3G

Settings
# exclusive inclusive rows x rows loops node
1. 0.003 2,371.773 ↑ 1.0 10 1

Limit (cost=1,078,870.53..1,079,036.83 rows=10 width=1,435) (actual time=2,371.763..2,371.773 rows=10 loops=1)

  • Buffers: shared hit=392493
2. 0.015 2,371.770 ↑ 1.2 10 1

Result (cost=1,078,870.53..1,079,070.09 rows=12 width=1,435) (actual time=2,371.762..2,371.770 rows=10 loops=1)

  • Buffers: shared hit=392493
3. 298.464 2,371.745 ↑ 1.2 10 1

Sort (cost=1,078,870.53..1,078,870.56 rows=12 width=599) (actual time=2,371.744..2,371.745 rows=10 loops=1)

  • Sort Key: a.modl_id DESC, ((COALESCE(a.inq_cnt, 0) + COALESCE(a.mngr_inq_cnt, 0))) DESC, a.reg_dtm DESC
  • Sort Method: top-N heapsort Memory: 41kB
  • Buffers: shared hit=392493
4. 266.931 2,073.281 ↓ 32,797.3 393,568 1

Nested Loop Left Join (cost=13,728.97..1,078,870.32 rows=12 width=599) (actual time=249.104..2,073.281 rows=393,568 loops=1)

  • Join Filter: ((b.teacher_id)::text = (a.teacher_id)::text)
  • Buffers: shared hit=392493
5. 1,611.326 1,806.350 ↓ 32,797.3 393,568 1

Bitmap Heap Scan on bbd_notiarcl a (cost=13,728.69..1,078,861.81 rows=12 width=582) (actual time=249.079..1,806.350 rows=393,568 loops=1)

  • Recheck Cond: (((teacher_id)::text = '200211'::text) AND (bbs_no = 2007) AND ((open_yn)::text = 'Y'::text))
  • Rows Removed by Index Recheck: 1234048
  • Filter: (((title)::text !~~ '%셀프모의고사%'::text) AND (notiarcl_no = sort_bais_sntnc_no) AND ((org_sntnc_incl_yn)::text = 'N'::text) AND ((COALESCE(entexam_matr_div_cd, ''::character varying))::text = ''::text))
  • Rows Removed by Filter: 395278
  • Heap Blocks: exact=220917 lossy=168546
  • Buffers: shared hit=392490
6. 195.024 195.024 ↓ 1.6 788,846 1

Bitmap Index Scan on ix_bbs_bbd_notiarcl_28 (cost=0.00..13,728.69 rows=491,850 width=0) (actual time=195.024..195.024 rows=788,846 loops=1)

  • Index Cond: (((teacher_id)::text = '200211'::text) AND (bbs_no = 2007) AND ((open_yn)::text = 'Y'::text))
  • Buffers: shared hit=3027
7. 0.000 0.000 ↑ 1.0 1 393,568

Materialize (cost=0.28..8.30 rows=1 width=20) (actual time=0.000..0.000 rows=1 loops=393,568)

  • Buffers: shared hit=3
8. 0.018 0.018 ↑ 1.0 1 1

Index Scan using ix_lecture_ltc_teacher_03 on ltc_teacher b (cost=0.28..8.29 rows=1 width=20) (actual time=0.018..0.018 rows=1 loops=1)

  • Index Cond: ((teacher_id)::text = '200211'::text)
  • Buffers: shared hit=3
9.          

SubPlan (for Result)

10. 0.010 0.010 ↓ 0.0 0 10

Index Scan using ix_member_mmm_comm_cd_01 on mmm_comm_cd (cost=0.29..8.31 rows=1 width=21) (actual time=0.001..0.001 rows=0 loops=10)

  • Index Cond: (((cd_clasf_cd)::text = '0077'::text) AND ((cd)::text = (a.scn_cd)::text))
11. 0.000 0.000 ↓ 0.0 0 10

Index Scan using ix_member_mmm_comm_cd_01 on mmm_comm_cd mmm_comm_cd_1 (cost=0.29..8.31 rows=1 width=21) (actual time=0.000..0.000 rows=0 loops=10)

  • Index Cond: (((cd_clasf_cd)::text = '0107'::text) AND ((cd)::text = (a.dom_cd)::text))