explain.depesz.com

PostgreSQL's explain analyze made readable

Result: 2uoU : Optimization for: plan #sg35

Settings

Optimization path:

# exclusive inclusive rows x rows loops node
1. 0.002 0.054 ↑ 1.0 1 1

Limit (cost=0.42..8.65 rows=1 width=189) (actual time=0.053..0.054 rows=1 loops=1)

2. 0.001 0.052 ↑ 21.0 1 1

Nested Loop Left Join (cost=0.42..173.21 rows=21 width=189) (actual time=0.052..0.052 rows=1 loops=1)

  • Join Filter: (nodeslogical.nl_id = wifiaccesspointsassignmenthistory.wapah_nl_id)
  • Rows Removed by Join Filter: 4
3. 0.001 0.046 ↑ 21.0 1 1

Nested Loop Left Join (cost=0.42..97.71 rows=21 width=35) (actual time=0.046..0.046 rows=1 loops=1)

4. 0.002 0.033 ↑ 21.0 1 1

Nested Loop (cost=0.27..45.78 rows=21 width=37) (actual time=0.033..0.033 rows=1 loops=1)

  • Join Filter: (wifiaccesspoints.wap_basemac = wifiaeroscouttagspositionhistory.watph_wap_basemac)
  • Rows Removed by Join Filter: 2
5. 0.021 0.021 ↑ 21.0 1 1

Index Only Scan using watph_wat_mac_index on wifiaeroscouttagspositionhistory (cost=0.27..42.94 rows=21 width=22) (actual time=0.021..0.021 rows=1 loops=1)

  • Index Cond: (watph_wat_mac = '00:0c:cc:49:17:64'::macaddr)
  • Heap Fetches: 1
6. 0.003 0.010 ↑ 2.0 3 1

Materialize (cost=0.00..1.09 rows=6 width=15) (actual time=0.009..0.010 rows=3 loops=1)

7. 0.007 0.007 ↑ 2.0 3 1

Seq Scan on wifiaccesspoints (cost=0.00..1.06 rows=6 width=15) (actual time=0.007..0.007 rows=3 loops=1)

8. 0.012 0.012 ↓ 0.0 0 1

Index Scan using wapah_unique_active_mac on wifiaccesspointsassignmenthistory (cost=0.14..2.45 rows=1 width=10) (actual time=0.012..0.012 rows=0 loops=1)

  • Index Cond: (wapah_basemac = wifiaeroscouttagspositionhistory.watph_wap_basemac)
9. 0.001 0.005 ↑ 50.0 4 1

Materialize (cost=0.00..13.00 rows=200 width=158) (actual time=0.004..0.005 rows=4 loops=1)

10. 0.004 0.004 ↑ 50.0 4 1

Seq Scan on nodeslogical (cost=0.00..12.00 rows=200 width=158) (actual time=0.003..0.004 rows=4 loops=1)