explain.depesz.com

PostgreSQL's explain analyze made readable

Result: qSC9 : Optimization for: Optimization for: Optimization for: Optimization for: plan #SD18; plan #wb5W; plan #QfXa; plan #Z4Wx

Settings

Optimization path:

Optimization(s) for this plan:

# exclusive inclusive rows x rows loops node
1. 0.002 0.077 ↑ 1.0 1 1

Limit (cost=40.37..40.37 rows=1 width=189) (actual time=0.075..0.077 rows=1 loops=1)

2. 0.009 0.075 ↑ 19.0 1 1

Sort (cost=40.37..40.41 rows=19 width=189) (actual time=0.075..0.075 rows=1 loops=1)

  • Sort Key: wifiaeroscouttagspositionhistory.watph_from DESC
  • Sort Method: top-N heapsort Memory: 25kB
3. 0.006 0.066 ↑ 1.1 18 1

Hash Join (cost=27.45..40.27 rows=19 width=189) (actual time=0.060..0.066 rows=18 loops=1)

  • Hash Cond: (wifiaeroscouttagspositionhistory.watph_wap_basemac = wifiaccesspoints.wap_basemac)
4. 0.006 0.051 ↑ 1.1 18 1

Hash Right Join (cost=26.32..39.06 rows=19 width=180) (actual time=0.047..0.051 rows=18 loops=1)

  • Hash Cond: (wifiaccesspointsassignmenthistory.wapah_basemac = wifiaeroscouttagspositionhistory.watph_wap_basemac)
5. 0.007 0.015 ↑ 8.0 1 1

Hash Right Join (cost=14.42..26.95 rows=8 width=164) (actual time=0.011..0.015 rows=1 loops=1)

  • Hash Cond: (nodeslogical.nl_id = wifiaccesspointsassignmenthistory.wapah_nl_id)
6. 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)

7. 0.001 0.004 ↑ 8.0 1 1

Hash (cost=14.32..14.32 rows=8 width=10) (actual time=0.004..0.004 rows=1 loops=1)

  • Buckets: 1024 Batches: 1 Memory Usage: 9kB
8. 0.001 0.003 ↑ 8.0 1 1

Bitmap Heap Scan on wifiaccesspointsassignmenthistory (cost=4.19..14.32 rows=8 width=10) (actual time=0.003..0.003 rows=1 loops=1)

  • Recheck Cond: (wapah_end IS NULL)
  • Heap Blocks: exact=1
9. 0.002 0.002 ↑ 8.0 1 1

Bitmap Index Scan on wapah_unique_active_logical (cost=0.00..4.18 rows=8 width=0) (actual time=0.002..0.002 rows=1 loops=1)

10. 0.003 0.030 ↑ 1.1 18 1

Hash (cost=11.66..11.66 rows=19 width=22) (actual time=0.030..0.030 rows=18 loops=1)

  • Buckets: 1024 Batches: 1 Memory Usage: 9kB
11. 0.014 0.027 ↑ 1.1 18 1

Bitmap Heap Scan on wifiaeroscouttagspositionhistory (cost=4.42..11.66 rows=19 width=22) (actual time=0.017..0.027 rows=18 loops=1)

  • Recheck Cond: ((watph_wat_mac = '00:0c:cc:49:17:64'::macaddr) AND (watph_wap_basemac IS NOT NULL))
  • Heap Blocks: exact=6
12. 0.013 0.013 ↑ 1.1 18 1

Bitmap Index Scan on watph_wat_mac_index (cost=0.00..4.42 rows=19 width=0) (actual time=0.012..0.013 rows=18 loops=1)

  • Index Cond: (watph_wat_mac = '00:0c:cc:49:17:64'::macaddr)
13. 0.002 0.009 ↑ 1.0 6 1

Hash (cost=1.06..1.06 rows=6 width=15) (actual time=0.009..0.009 rows=6 loops=1)

  • Buckets: 1024 Batches: 1 Memory Usage: 9kB
14. 0.007 0.007 ↑ 1.0 6 1

Seq Scan on wifiaccesspoints (cost=0.00..1.06 rows=6 width=15) (actual time=0.005..0.007 rows=6 loops=1)