explain.depesz.com

PostgreSQL's explain analyze made readable

Result: ZEHC

Settings
# exclusive inclusive rows x rows loops node
1. 0.002 0.521 ↑ 1.0 1 1

Limit (cost=185.84..185.85 rows=1 width=185) (actual time=0.520..0.521 rows=1 loops=1)

2. 0.009 0.519 ↑ 1.0 1 1

Sort (cost=185.84..185.85 rows=1 width=185) (actual time=0.519..0.519 rows=1 loops=1)

  • Sort Key: wifiaeroscouttagspositionhistory.watph_from DESC
  • Sort Method: top-N heapsort Memory: 25kB
3. 0.000 0.510 ↓ 13.0 13 1

Nested Loop Left Join (cost=44.25..185.83 rows=1 width=185) (actual time=0.029..0.510 rows=13 loops=1)

4. 0.007 0.498 ↓ 13.0 13 1

Nested Loop Left Join (cost=44.11..185.64 rows=1 width=35) (actual time=0.026..0.498 rows=13 loops=1)

5. 0.007 0.478 ↓ 13.0 13 1

Hash Left Join (cost=43.98..185.47 rows=1 width=32) (actual time=0.017..0.478 rows=13 loops=1)

  • Hash Cond: (wifiaeroscouttagspositionhistory.watph_wap_basemac = wifiaccesspointsassignmenthistory.wapah_basemac)
  • Filter: (wifiaccesspointsassignmenthistory.wapah_end IS NULL)
6. 0.465 0.465 ↑ 1.1 13 1

Seq Scan on wifiaeroscouttagspositionhistory (cost=0.00..137.96 rows=14 width=22) (actual time=0.008..0.465 rows=13 loops=1)

  • Filter: (watph_wat_mac = '00:0c:cc:4f:ea:87'::macaddr)
  • Rows Removed by Filter: 6263
7. 0.003 0.006 ↑ 503.3 3 1

Hash (cost=25.10..25.10 rows=1,510 width=18) (actual time=0.005..0.006 rows=3 loops=1)

  • Buckets: 2048 Batches: 1 Memory Usage: 17kB
8. 0.003 0.003 ↑ 503.3 3 1

Seq Scan on wifiaccesspointsassignmenthistory (cost=0.00..25.10 rows=1,510 width=18) (actual time=0.003..0.003 rows=3 loops=1)

9. 0.013 0.013 ↑ 1.0 1 13

Index Scan using wifiaccesspoints_pkey on wifiaccesspoints (cost=0.13..0.16 rows=1 width=15) (actual time=0.001..0.001 rows=1 loops=13)

  • Index Cond: (wap_basemac = wifiaccesspointsassignmenthistory.wapah_basemac)
10. 0.013 0.013 ↑ 1.0 1 13

Index Scan using nodeslogical_pkey on nodeslogical (cost=0.14..0.19 rows=1 width=158) (actual time=0.001..0.001 rows=1 loops=13)

  • Index Cond: (nl_id = wifiaccesspointsassignmenthistory.wapah_nl_id)