explain.depesz.com

PostgreSQL's explain analyze made readable

Result: o3dn

Settings
# exclusive inclusive rows x rows loops node
1. 4.684 139,656.000 ↑ 1.1 1,876 1

Seq Scan on symbols s (cost=0.00..181,924.80 rows=2,028 width=20) (actual time=0.432..139,656.000 rows=1,876 loops=1)

  • Buffers: shared hit=11884366 dirtied=36
2.          

SubPlan (forSeq Scan)

3. 3.752 139,270.488 ↑ 1.0 1 1,876

Limit (cost=0.71..44.85 rows=1 width=16) (actual time=74.237..74.238 rows=1 loops=1,876)

  • Buffers: shared hit=11825923
4. 0.000 139,266.736 ↑ 13,455.0 1 1,876

Merge Append (cost=0.71..593,878.07 rows=13,455 width=16) (actual time=74.236..74.236 rows=1 loops=1,876)

  • Sort Key: t."time
  • Buffers: shared hit=11825923
5. 1.876 1.876 ↓ 0.0 0 1,876

Index Scan using tickers_time_symbol_idx on tickers t (cost=0.12..2.34 rows=1 width=16) (actual time=0.001..0.001 rows=0 loops=1,876)

  • Index Cond: (("time" > '2018-12-09 00:00:00+00'::timestamp with time zone) AND ((symbol)::text = (s.symbol)::text))
  • Buffers: shared hit=1876
6. 139,264.860 139,264.860 ↑ 13,454.0 1 1,876

Index Scan using _hyper_1_5_chunk_time_symbol_idx on _hyper_1_5_chunk t_1 (cost=0.57..593,774.80 rows=13,454 width=16) (actual time=74.235..74.235 rows=1 loops=1,876)

  • Index Cond: (("time" > '2018-12-09 00:00:00+00'::timestamp with time zone) AND ((symbol)::text = (s.symbol)::text))
  • Buffers: shared hit=11824047
7. 1.876 380.828 ↑ 1.0 1 1,876

Limit (cost=0.71..44.85 rows=1 width=16) (actual time=0.203..0.203 rows=1 loops=1,876)

  • Buffers: shared hit=58432 dirtied=36
8. 3.752 378.952 ↑ 13,455.0 1 1,876

Merge Append (cost=0.71..593,878.07 rows=13,455 width=16) (actual time=0.202..0.202 rows=1 loops=1,876)

  • Sort Key: t_2."time" DESC
  • Buffers: shared hit=58432 dirtied=36
9. 1.876 1.876 ↓ 0.0 0 1,876

Index Scan Backward using tickers_time_symbol_idx on tickers t_2 (cost=0.12..2.34 rows=1 width=16) (actual time=0.001..0.001 rows=0 loops=1,876)

  • Index Cond: (("time" > '2018-12-09 00:00:00+00'::timestamp with time zone) AND ((symbol)::text = (s.symbol)::text))
  • Buffers: shared hit=1876
10. 373.324 373.324 ↑ 13,454.0 1 1,876

Index Scan Backward using _hyper_1_5_chunk_time_symbol_idx on _hyper_1_5_chunk t_3 (cost=0.57..593,774.80 rows=13,454 width=16) (actual time=0.199..0.199 rows=1 loops=1,876)

  • Index Cond: (("time" > '2018-12-09 00:00:00+00'::timestamp with time zone) AND ((symbol)::text = (s.symbol)::text))
  • Buffers: shared hit=56556 dirtied=36