Hi there,
If it's possible, I would really appreciate any hints or help on an issue
I've been facing lately.
I'm running two instance of Postgres locally: 9.4.4 (operational db) and
9.5beta1 (analytical db). I've already imported schema to analytical db and
while doing the following query I find very different query plans being
executed:
Query:
EXPLAIN ANALYZE VERBOSE SELECT
o.id AS id,
o.company_id AS company_id,
o.created_at::date AS created_at,
COALESCE(o.assignee_id, 0) AS assignee_id,
(o.tax_treatment)::text AS tax_treatment,
COALESCE(o.tax_override, 0) AS tax_override,
COALESCE(o.stock_location_id, 0) AS stock_location_id,
COALESCE(l.label, 'N/A')::text AS stock_location_name,
COALESCE(sa.country, 'N/A')::text AS shipping_address_country,
COALESCE(o.tags, ARRAY[]::text[]) AS tags
FROM orders AS o
INNER JOIN locations AS l ON l.id = o.stock_location_id
INNER JOIN addresses AS sa ON sa.id = o.shipping_address_id
WHERE o.account_id = <some_value> AND l.account_id = <another_value>
LIMIT 10;
Plan when I run it locally on operational db:
Limit (cost=747.62..811.46 rows=1 width=76) (actual time=28.208..28.397
rows=10 loops=1)
Output: o.id, o.company_id, ((o.created_at)::date),
(COALESCE(o.assignee_id, 0)), ((o.tax_treatment)::text),
(COALESCE(o.tax_override, 0::numeric)), (COALESCE(o.stock_location_id, 0)),
((COALESCE(l.label, 'N/A'::character varying))::text),
((COALESCE(sa.country, 'N/A'::character varying))::text), (COALESCE(o.tags,
'{}'::character varying[]))
-> Nested Loop (cost=747.62..811.46 rows=1 width=76) (actual
time=28.208..28.395 rows=10 loops=1)
Output: o.id, o.company_id, (o.created_at)::date,
COALESCE(o.assignee_id, 0), (o.tax_treatment)::text,
COALESCE(o.tax_override, 0::numeric), COALESCE(o.stock_location_id, 0),
(COALESCE(l.label, 'N/A'::character varying))::text, (COALESCE(sa.country,
'N/A'::character varying))::text, COALESCE(o.tags, '{}'::character
varying[])
-> Nested Loop (cost=747.19..807.15 rows=1 width=73) (actual
time=28.164..28.211 rows=10 loops=1)
Output: o.id, o.company_id, o.created_at, o.assignee_id,
o.tax_treatment, o.tax_override, o.stock_location_id, o.tags,
o.shipping_address_id, l.label
-> Index Scan using index_locations_on_account_id on
public.locations l (cost=0.29..8.31 rows=1 width=20) (actual
time=0.025..0.025 rows=1 loops=1)
Output: l.id, l.address1, l.address2, l.city, l.country,
l.zip_code, l.suburb, l.state, l.label, l.status, l.latitude, l.longitude,
l.created_at, l.updated_at, l.account_id, l.holds_stock
Index Cond: (l.account_id = 18799)
-> Bitmap Heap Scan on public.orders o (cost=746.90..798.71
rows=13 width=57) (actual time=28.133..28.176 rows=10 loops=1)
Output: o.id, o.account_id, o.company_id, o.status,
o.invoice_number, o.reference_number, o.due_at, o.issued_at, o.user_id,
o.notes, o.created_at, o.updated_at, o.order_number, o.billing_address_id,
o.shipping_address_id, o.payment_status, o.email, o.fulfillment_status,
o.phone_number, o.assignee_id, o.tax_treatment, o.tax_override,
o.tax_label_override, o.stock_location_id, o.currency_id, o.source,
o.source_url, o.demo, o.invoice_status, o.ship_at, o.source_id, o.search,
o.default_price_list_id, o.contact_id, o.return_status, o.tags,
o.packed_status, o.returning_status, o.shippability_status,
o.backordering_status
Recheck Cond: ((o.stock_location_id = l.id) AND
(o.account_id = 18799))
Heap Blocks: exact=7
-> BitmapAnd (cost=746.90..746.90 rows=13 width=0)
(actual time=23.134..23.134 rows=0 loops=1)
-> Bitmap Index Scan on
index_orders_on_stock_location_id_manual (cost=0.00..18.02 rows=745
width=0) (actual time=9.282..9.282 rows=40317 loops=1)
Index Cond: (o.stock_location_id = l.id)
-> Bitmap Index Scan on index_orders_on_account_id
(cost=0.00..718.94 rows=38735 width=0) (actual time=9.856..9.856
rows=40317 loops=1)
Index Cond: (o.account_id = 18799)
-> Index Scan using addresses_pkey on public.addresses sa
(cost=0.43..4.30 rows=1 width=11) (actual time=0.015..0.016 rows=1
loops=10)
Output: sa.id, sa.company_id, sa.address1, sa.city, sa.country,
sa.zip_code, sa.created_at, sa.updated_at, sa.suburb, sa.state, sa.label,
sa.status, sa.address2, sa.phone_number, sa.email, sa.company_name,
sa.latitude, sa.longitude, sa.first_name, sa.last_name
Index Cond: (sa.id = o.shipping_address_id)
Planning time: 1.136 ms
Execution time: 28.621 ms
(23 rows)
Plan when I run it from analytical db via FDW:
Limit (cost=300.00..339.95 rows=1 width=1620) (actual
time=7630.240..82368.326 rows=10 loops=1)
Output: o.id, o.company_id, ((o.created_at)::date),
(COALESCE(o.assignee_id, 0)), ((o.tax_treatment)::text),
(COALESCE(o.tax_override, '0'::numeric)), (COALESCE(o.stock_location_id,
0)), ((COALESCE(l.label, 'N/A'::character varying))::
text), ((COALESCE(sa.country, 'N/A'::character varying))::text),
(COALESCE(o.tags, '{}'::character varying[]))
-> Nested Loop (cost=300.00..339.95 rows=1 width=1620) (actual
time=7630.238..82368.314 rows=10 loops=1)
Output: o.id, o.company_id, (o.created_at)::date,
COALESCE(o.assignee_id, 0), (o.tax_treatment)::text,
COALESCE(o.tax_override, '0'::numeric), COALESCE(o.stock_location_id, 0),
(COALESCE(l.label, 'N/A'::character varying))::text,
(COALESCE(sa.country, 'N/A'::character varying))::text, COALESCE(o.tags,
'{}'::character varying[])
Join Filter: (o.shipping_address_id = sa.id)
Rows Removed by Join Filter: 19227526
-> Nested Loop (cost=200.00..223.58 rows=1 width=1108) (actual
time=69.758..69.812 rows=10 loops=1)
Output: o.id, o.company_id, o.created_at, o.assignee_id,
o.tax_treatment, o.tax_override, o.stock_location_id, o.tags,
o.shipping_address_id, l.label
Join Filter: (o.stock_location_id = l.id)
Rows Removed by Join Filter: 18
-> Foreign Scan on remote.orders o (cost=100.00..111.67
rows=1 width=592) (actual time=68.009..68.014 rows=10 loops=1)
Output: o.id, o.account_id, o.company_id, o.status,
o.invoice_number, o.reference_number, o.due_at, o.issued_at, o.user_id,
o.notes, o.created_at, o.updated_at, o.order_number, o.billing_address_id,
o.shipping_address
_id, o.payment_status, o.email, o.fulfillment_status, o.phone_number,
o.assignee_id, o.tax_treatment, o.tax_override, o.tax_label_override,
o.stock_location_id, o.currency_id, o.source, o.source_url, o.demo,
o.invoice_status, o.ship_at, o
.source_id, o.search, o.default_price_list_id, o.contact_id,
o.return_status, o.tags, o.packed_status, o.returning_status,
o.shippability_status, o.backordering_status
Remote SQL: SELECT id, company_id, created_at,
shipping_address_id, assignee_id, tax_treatment, tax_override,
stock_location_id, tags FROM public.orders WHERE ((account_id = 18799))
-> Foreign Scan on remote.locations l (cost=100.00..111.90
rows=1 width=520) (actual time=0.174..0.174 rows=3 loops=10)
Output: l.id, l.address1, l.address2, l.city,
l.country, l.zip_code, l.suburb, l.state, l.label, l.status, l.latitude,
l.longitude, l.created_at, l.updated_at, l.account_id, l.holds_stock
Remote SQL: SELECT id, label FROM public.locations
WHERE ((account_id = 18799))
-> Foreign Scan on remote.addresses sa (cost=100.00..114.50
rows=150 width=520) (actual time=0.634..8029.415 rows=1922754 loops=10)
Output: sa.id, sa.company_id, sa.address1, sa.city,
sa.country, sa.zip_code, sa.created_at, sa.updated_at, sa.suburb, sa.state,
sa.label, sa.status, sa.address2, sa.phone_number, sa.email,
sa.company_name, sa.latitude, sa.l
ongitude, sa.first_name, sa.last_name
Remote SQL: SELECT id, country FROM public.addresses
Planning time: 0.209 ms
Execution time: 82391.610 ms
(21 rows)
Time: 82393.211 ms
What am I doing wrong ? really appreciate any guidance possible. Thank you
very much for taking the time to helping me with this.
Best Regards,
Mohammad
