Обсуждение: Postgres cursor taking 2 hrs to update the table

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Postgres cursor taking 2 hrs to update the table

От
M Tarkeshwar Rao
Дата:

Hi,

 

I have the 10 application processes(each process having 12 threads and each of have updating 8 million rows in the shared memory) which are reading the data from single postgres database. We are using database cursors in C++ to fetch the data and updating the shared memory. There is the timer attached, where all the processor threads going to fetch the data.

 

The issue is that sometimes it is fetching all the data in few seconds and sometimes it is taking 2 hrs.

 

What could be the issue. Can you please guide me to resolve the issue?

 

Regards

Tarkeshwar

Re: Postgres cursor taking 2 hrs to update the table

От
Adrian Klaver
Дата:
On 12/24/19 2:32 AM, M Tarkeshwar Rao wrote:
> Hi,
> 
> I have the 10 application processes(each process having 12 threads and 
> each of have updating 8 million rows in the shared memory) which are 
> reading the data from single postgres database. We are using database 
> cursors in C++ to fetch the data and updating the shared memory. There 
> is the timer attached, where all the processor threads going to fetch 
> the data.
> 
> The issue is that sometimes it is fetching all the data in few seconds 
> and sometimes it is taking 2 hrs.
> 
> /What could be the issue. Can you please guide me to resolve the issue?/

By providing more information:

1) Postgres version?

2) OS and version?

3) Where the client and server are relative to each other?

4) Any relevant information from the Postgres log?

You might also look at:

https://www.postgresql.org/docs/11/auto-explain.html

> 
> Regards
> 
> Tarkeshwar
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com