1
我有一個Postgres(版本9.5.4)表geo
包含738884條記錄的國家地理數據的結構如下:由kind
場性能後代的搜索使用的Postgres intarray場
Table "public.geo"
Column | Type | Modifiers | Storage | Stats target | Description
-------------+-----------------------------+-----------+----------+--------------+-------------
id | integer | not null | plain | |
kind | character varying(255) | | extended | |
name | character varying(255) | | extended | |
is_owner | integer | | plain | |
path_array | integer[] | | extended | |
Indexes:
"geo_pkey" PRIMARY KEY, btree (id)
"kind_index" btree (kind)
"path_array_idx" gin (path_array gin__int_ops)
記錄有層次:country
→province
→area
→locality
。該層次結構存儲在path_array
字段中,作爲祖先和行的自我ID的數組。
實施例:
17239123 locality Moscow 1 {17073865,17073877,17073958,17239123}
我已經安裝intarray延伸,並加入適當的索引path_array
字段。
現在我有一堆recods的id可以有任何種類(從國家到地區),我需要選擇類型爲locality
的所有後代(即在其path_array
中有任何此ID的記錄)。
這是我的查詢:
SELECT
id
FROM geo
WHERE
kind = 'locality'
AND is_owner = 1
AND path_array && '{17073888,17073984,17073885,17073905,17073958,17073927,17073908,17073952,17073948,17073947,17073917,17073944,17073919,17073922,17073914,17073937,17073895,17073904,17073911,17073949,17073938,17073957,17073900,17073915,17073936,17073887,17073933,17073939,17073956,17073884,17073901,17073881,17153202,17073916,17073945,17073883,17073943,17073909,17073950,17073942,17073906,17073886,17073910,17073882,17073941,17073891,17073929,17073928,17073903,17073912,17073930,17073898,17073899,17073954}'::integer[]
這裏是EXPLAIN ANALYZE
輸出:
Bitmap Heap Scan on geo (cost=1418.04..1532.99 rows=8 width=4) (actual time=685.183..723.330 rows=20984 loops=1)
Recheck Cond: ((is_owner = 1) AND (path_array && '{17073888,17073984,17073885,17073905,17073958,17073927,17073908,17073952,17073948,17073947,17073917,17073944,17073919,17073922,17073914,17073937,17073895,17073904,17073911,17073949,17073938,17073957,17073900,17073915,17073936,17073887,17073933,17073939,17073956,17073884,17073901,17073881,17153202,17073916,17073945,17073883,17073943,17073909,17073950,17073942,17073906,17073886,17073910,17073882,17073941,17073891,17073929,17073928,17073903,17073912,17073930,17073898,17073899,17073954}'::integer[]))
Filter: ((kind)::text = 'locality'::text)
Rows Removed by Filter: 2037
Heap Blocks: exact=17106
-> BitmapAnd (cost=1418.04..1418.04 rows=29 width=0) (actual time=681.154..681.154 rows=0 loops=1)
-> Bitmap Index Scan on is_owner_index (cost=0.00..544.24 rows=29309 width=0) (actual time=5.493..5.493 rows=29201 loops=1)
Index Cond: (is_owner = 1)
-> Bitmap Index Scan on path_array_idx (cost=0.00..873.54 rows=739 width=0) (actual time=667.888..667.888 rows=607440 loops=1)
Index Cond: (path_array && '{17073888,17073984,17073885,17073905,17073958,17073927,17073908,17073952,17073948,17073947,17073917,17073944,17073919,17073922,17073914,17073937,17073895,17073904,17073911,17073949,17073938,17073957,17073900,17073915,17073936,17073887,17073933,17073939,17073956,17073884,17073901,17073881,17153202,17073916,17073945,17073883,17073943,17073909,17073950,17073942,17073906,17073886,17073910,17073882,17073941,17073891,17073929,17073928,17073903,17073912,17073930,17073898,17073899,17073954}'::integer[])
Planning time: 0.212 ms
Execution time: 727.370 ms
上面的查詢耗時約700毫秒,我相信這是非常緩慢的。 我是對的還是我要求太高?
根據解釋計劃,查詢只需要700ms,而不是1.4秒 –
這是網絡延遲問題。修復它並增加了可能的解決方案 – bbrodriges
對我來說看起來很不錯 - afaiac,繼續並作爲回答發佈。 – shaunc