Created
January 26, 2021 10:24
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############ 1 | |
UPDATE tenk1 SET hundred = hundred + 1 WHERE unique1 < 100; | |
QUERY PLAN | |
-------------------------------------------------------------------------------------------------------------------------------- | |
Update on tenk1 (cost=5.07..229.46 rows=101 width=250) (actual time=14.628..14.628 rows=0 loops=1) | |
-> Bitmap Heap Scan on tenk1 (cost=5.07..229.46 rows=101 width=250) (actual time=0.101..0.439 rows=100 loops=1) | |
Recheck Cond: (unique1 < 100) | |
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1) | |
Index Cond: (unique1 < 100) | |
############ 2 | |
SELECT * FROM tenk1 WHERE unique1 < 100 AND unique2 > 9000; | |
QUERY PLAN | |
--------------------------------------------------------------------------------------------------------------------------------- | |
Bitmap Heap Scan on tenk1 (cost=25.08..60.21 rows=10 width=244) (actual time=0.323..0.342 rows=10 loops=1) | |
Recheck Cond: ((unique1 < 100) AND (unique2 > 9000)) | |
Buffers: shared hit=15 | |
-> BitmapAnd (cost=25.08..25.08 rows=10 width=0) (actual time=0.309..0.309 rows=0 loops=1) | |
Buffers: shared hit=7 | |
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1) | |
Index Cond: (unique1 < 100) | |
Buffers: shared hit=2 | |
-> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1) | |
Index Cond: (unique2 > 9000) | |
Buffers: shared hit=5 | |
############ 3 | |
EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100 AND stringu1 = 'xxx'; | |
QUERY PLAN | |
-------------------------------------------------------------------------- | |
Bitmap Heap Scan on tenk1 (cost=5.01..229.40 rows=1 width=244) | |
Recheck Cond: (unique1 < 100) | |
Filter: (stringu1 = 'xxx'::name) | |
-> Bitmap Index Scan on tenk1_unique1 | |
(cost=0.00..5.04 rows=101 width=0) | |
Index Cond: (unique1 < 100) |
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