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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Samir Magar <samirmagar8@gmail.com>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: query performance issue
Date: Wed, 15 Nov 2017 14:12:10 +0100
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2017-11-15 13:54 GMT+01:00 Samir Magar <samirmagar8@gmail.com>:

> please find the EXPLAIN ANALYZE output.
>
> On Wed, Nov 15, 2017 at 3:13 PM, Pavel Stehule <pavel.stehule@gmail.com>
> wrote:
>
>> Hi
>>
>> please send EXPLAIN ANALYZE output.
>>
>> Regards
>>
>> Pavel
>>
>> 2017-11-15 10:33 GMT+01:00 Samir Magar <samirmagar8@gmail.com>:
>>
>>> Hello,
>>> I am having performance issues with one of the query.
>>> The query is taking 39 min to fetch 3.5 mil records.
>>>
>>> I want to reduce that time to 15 mins.
>>> could you please suggest something to its performance?
>>>
>>> server configuration:
>>>  CPUs = 4
>>> memory = 16 GM
>>> shared_buffers = 3 GB
>>> work_mem = 100MB
>>> effective_cache_size = 12 GB
>>>
>>> we are doing the vacuum/analyze regularly on the database.
>>>
>>> attached is the query with its explain plan.
>>>
>>>

There is wrong plan due wrong estimation

for this query you should to penalize nested loop

set enable_nestloop to off;

before evaluation of this query


Thanks,
>>> Samir Magar
>>>
>>>
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>>>
>>
>

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  Subject: Re: query performance issue
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