を選ぶなぜ私はこのクエリは少ないし、100ミリ秒で高速に実行されますが、時にはそれは非常に、いくつかのc_phone2のために4秒にid_organizationの組み合わせを遅く実行を開始する時間のほとんどは、単純なクエリPostgresが間違った実行計画
select count(*)
from taxi_order.ta_orders o
inner join public.t_bases b on b.id = o.id_base
where o.c_phone2 = ''
and b.id_organization = 1
and o.c_date_end < '2017-12-01'::date
group by date_trunc('month', o.c_date_end);
を持っています。速い場合の
実行計画:遅い場合の
HashAggregate (cost=7005.05..7005.62 rows=163 width=8)
Group Key: date_trunc('month'::text, o.c_date_end)
-> Hash Join (cost=94.30..7004.23 rows=163 width=8)
Hash Cond: (o.id_base = b.id)
-> Index Scan using ix_ta_orders_c_phone2 on ta_orders o (cost=0.57..6899.41 rows=2806 width=12)
Index Cond: ((c_phone2)::text = $3)
Filter: (c_date_end < $4)
-> Hash (cost=93.26..93.26 rows=133 width=4)
-> Bitmap Heap Scan on t_bases b (cost=4.71..93.26 rows=133 width=4)
Recheck Cond: (id_organization = $2)
-> Bitmap Index Scan on ix_t_bases_id_organization (cost=0.00..4.68 rows=133 width=0)
Index Cond: (id_organization = $2)
実行計画:
HashAggregate (cost=6604.97..6604.98 rows=1 width=8)
Group Key: date_trunc('month'::text, o.c_date_end)
-> Nested Loop (cost=2195.33..6604.97 rows=1 width=8)
-> Bitmap Heap Scan on t_bases b (cost=2.29..7.78 rows=3 width=4)
Recheck Cond: (id_organization = $2)
-> Bitmap Index Scan on ix_t_bases_id_organization (cost=0.00..2.29 rows=3 width=0)
Index Cond: (id_organization = $2)
-> Bitmap Heap Scan on ta_orders o (cost=2193.04..2199.06 rows=3 width=12)
Recheck Cond: (((c_phone2)::text = $3) AND (id_base = b.id) AND (c_date_end < $4))
-> BitmapAnd (cost=2193.04..2193.04 rows=3 width=0)
-> Bitmap Index Scan on ix_ta_orders_c_phone2 (cost=0.00..58.84 rows=3423 width=0)
Index Cond: ((c_phone2)::text = $3)
-> Bitmap Index Scan on ix_ta_orders_id_base_date_end (cost=0.00..2133.66 rows=83472 width=0)
Index Cond: ((id_base = b.id) AND (c_date_end < $4))
クエリかんなは時々とても遅い無効計画を選択しますなぜ?テーブル用
EDIT
スキーマ:
craete table taxi_order.ta_orders (
id bigserial not null,
id_base integer not null,
c_phone2 character varying(30),
c_date_end timestamp with time zone,
...
CONSTRAINT pk_ta_orders PRIMARY KEY (id),
CONSTRAINT fk_ta_orders_t_bases REFERENCES public.t_bases (id)
);
craete table public.t_bases (
id serial not null,
id_organization integer not null,
...
CONSTRAINT pk_t_bases PRIMARY KEY (id)
);
ta_orders〜100Mの行は、〜2K行をt_bases。
EDIT2
遅い場合のために、分析説明:私はそれをスピードアップするためにすべてのクエリのために別のインデックスを作成することができます知っている
HashAggregate (cost=7005.05..7005.62 rows=163 width=8) (actual time=0.927..0.928 rows=1 loops=1)
Group Key: date_trunc('month'::text, o.c_date_end)
-> Hash Join (cost=94.30..7004.23 rows=163 width=8) (actual time=0.903..0.913 rows=2 loops=1)
Hash Cond: (o.id_base = b.id)
-> Index Scan using ix_ta_orders_c_phone2 on ta_orders o (cost=0.57..6899.41 rows=2806 width=12) (actual time=0.591..0.604 rows=4 loops=1)
Index Cond: ((c_phone2)::text = $3)
Filter: (c_date_end < $4)
Rows Removed by Filter: 2
-> Hash (cost=93.26..93.26 rows=133 width=4) (actual time=0.237..0.237 rows=133 loops=1)
Buckets: 1024 Batches: 1 Memory Usage: 13kB
-> Bitmap Heap Scan on t_bases b (cost=4.71..93.26 rows=133 width=4) (actual time=0.058..0.196 rows=133 loops=1)
Recheck Cond: (id_organization = $2)
Heap Blocks: exact=45
-> Bitmap Index Scan on ix_t_bases_id_organization (cost=0.00..4.68 rows=133 width=0) (actual time=0.044..0.044 rows=133 loops=1)
Index Cond: (id_organization = $2)
:
HashAggregate (cost=6355.29..6355.29 rows=1 width=8) (actual time=4075.847..4075.847 rows=1 loops=1)
Group Key: date_trunc('month'::text, o.c_date_end)
-> Nested Loop (cost=2112.10..6355.28 rows=1 width=8) (actual time=114.871..4075.803 rows=2 loops=1)
-> Bitmap Heap Scan on t_bases b (cost=2.29..7.78 rows=3 width=4) (actual time=0.061..0.375 rows=133 loops=1)
Recheck Cond: (id_organization = $2)
Heap Blocks: exact=45
-> Bitmap Index Scan on ix_t_bases_id_organization (cost=0.00..2.29 rows=3 width=0) (actual time=0.045..0.045 rows=133 loops=1)
Index Cond: (id_organization = $2)
-> Bitmap Heap Scan on ta_orders o (cost=2109.81..2115.83 rows=3 width=12) (actual time=30.638..30.638 rows=0 loops=133)
Recheck Cond: (((c_phone2)::text = $3) AND (id_base = b.id) AND (c_date_end < $4))
Heap Blocks: exact=2
-> BitmapAnd (cost=2109.81..2109.81 rows=3 width=0) (actual time=30.635..30.635 rows=0 loops=133)
-> Bitmap Index Scan on ix_ta_orders_c_phone2 (cost=0.00..58.85 rows=3427 width=0) (actual time=0.032..0.032 rows=6 loops=133)
Index Cond: ((c_phone2)::text = $3)
-> Bitmap Index Scan on ix_ta_orders_id_base_date_end (cost=0.00..2050.42 rows=80216 width=0) (actual time=30.108..30.108 rows=94206 loops=133)
Index Cond: ((id_base = b.id) AND (c_date_end < $4))
が速い場合のために、分析を説明してください。しかし、私は間違った計画を選ぶ理由は何かを知りたいですか?私の統計に何が間違っていますか?
もっと詳しい情報が必要だと思います。これらの2つのテーブルのスキーマは何ですか? –