explain.depesz.com

PostgreSQL's explain analyze made readable

Result: zaiB

Settings
# exclusive inclusive rows x rows loops node
1. 1.309 28.206 ↑ 1.0 1 1

Aggregate (cost=21,003.05..21,003.06 rows=1 width=32) (actual time=28.206..28.206 rows=1 loops=1)

  • Output: max((t1.data)::text)
  • Buffers: shared hit=7991 read=2027
  • I/O Timings: read=8.918
2. 3.204 26.897 ↓ 1.0 2,000 1

Nested Loop (cost=40.25..20,998.08 rows=1,987 width=33) (actual time=0.574..26.897 rows=2,000 loops=1)

  • Output: t1.data
  • Buffers: shared hit=7991 read=2027
  • I/O Timings: read=8.918
3. 3.364 3.693 ↓ 1.0 2,000 1

Bitmap Heap Scan on public.t1 (cost=39.83..5,814.00 rows=1,987 width=37) (actual time=0.558..3.693 rows=2,000 loops=1)

  • Output: t1.id, t1.milli, t1.centi, t1.data
  • Recheck Cond: (t1.milli = 1)
  • Heap Blocks: exact=2000
  • Buffers: shared hit=2008
4. 0.329 0.329 ↓ 1.0 2,000 1

Bitmap Index Scan on t1_milli (cost=0.00..39.33 rows=1,987 width=0) (actual time=0.329..0.329 rows=2,000 loops=1)

  • Index Cond: (t1.milli = 1)
  • Buffers: shared hit=8
5. 20.000 20.000 ↑ 1.0 1 2,000

Index Only Scan using t2_id on public.t2 (cost=0.43..7.63 rows=1 width=4) (actual time=0.010..0.010 rows=1 loops=2,000)

  • Output: t2.id
  • Index Cond: (t2.id = t1.id)
  • Heap Fetches: 2000
  • Buffers: shared hit=5983 read=2027
  • I/O Timings: read=8.918
Planning time : 0.326 ms
Execution time : 28.261 ms