Thread
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What is the best way to do this in Postgres
kunwar singh <krishsingh.111@gmail.com> — 2024-12-08T11:38:53Z
Hello Listers, Looking for your inputs on the most efficient way to do it in Postgres. What I want to do: === I want to spawn 10 concurrent sessions each executing a complex stored procedure with one of the parameters being the product ID. Example CALL process_product(curdate, region, productid=>1) ; CALL process_product(curdate, region, productid=>2) ; CALL process_product(curdate, region, productid=>3) ; CALL process_product(curdate, region, productid=>4) ; ... CALL process_product(curdate, region, productid=>10) ; Say I get a list of product IDs by running a big query Product ID ==== 1 2 3 4 .. 10 Additional Information === Everytime number of product ids will change. At a given time there should be no more than 10 concurrent sessions of process_product. I want to trigger these procedure calls once every hour. For a given hour the number of product IDs could range from 10 to 100 in total. I am using RDS Postgres v 15. Question === I know I can create a bash script or Python script , but I am wondering if there is a smarter way to do it in Postgres? -- Cheers, Kunwar
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Re: What is the best way to do this in Postgres
David G. Johnston <david.g.johnston@gmail.com> — 2024-12-08T15:26:43Z
On Sunday, December 8, 2024, kunwar singh <krishsingh.111@gmail.com> wrote: > > I know I can create a bash script or Python script , but I am wondering if > there is a smarter way to do it in Postgres? > > Your concurrency requirement makes doing it in the server quite difficult. Using anything that can launch multiple processes/threads and initiate one connect each is your best option. Many things can, so pick one you are familiar with. There is little complexity here that specialized tooling would be needed for. David J.
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Re: What is the best way to do this in Postgres
Carl Sopchak <carl@sopchak.me> — 2024-12-08T16:50:21Z
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> You could set up a queuing table to hold the product id's that need processing, removing that parameter from the proc (or all of them if all columns vary and are in the queuing table). Then the proc picks one product_id from the queue (using delete and capturing the data deleted data using RETURNING), processes it, then loops for the next product, terminating when there are none. A separate job runs to add new products needing processing to the queue table. This technique allows you to run as many simultaneous jobs as you need to go through all of the products in a timely manner without code changes. Also, if one fails, the others will pick up the slack since they all run until the queue is empty. I've used this technique before (although not in Postgres) and it works well.<br> <br> <br> <div class="moz-cite-prefix">On 12/8/24 10:26 AM, David G. Johnston wrote:<br> </div> <blockquote type="cite" cite="mid:CAKFQuwbkVaAHT+nBfwffZY89pWvqtkK4q0aOmX9PT3Hf7oz2sA@mail.gmail.com"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> On Sunday, December 8, 2024, kunwar singh <<a href="mailto:krishsingh.111@gmail.com" moz-do-not-send="true" class="moz-txt-link-freetext">krishsingh.111@gmail.com</a>> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div dir="ltr"> <div><br> </div> <div> <div style="font-family:Menlo,Monaco,"Courier New",monospace;font-size:12px;line-height:18px;white-space:pre-wrap"><div><font style="background-color:rgb(243,243,243)" color="#0000ff">I know I can create a bash script or Python script , but I am wondering if there is a smarter way to do it in Postgres?</font></div></div> </div> <br> </div> </blockquote> <div><br> </div> <div>Your concurrency requirement makes doing it in the server quite difficult. Using anything that can launch multiple processes/threads and initiate one connect each is your best option. Many things can, so pick one you are familiar with. There is little complexity here that specialized tooling would be needed for.</div> <div><br> </div> <div>David J. <br> </div> </blockquote> <br> </body> </html> -
Re: What is the best way to do this in Postgres
Erik Brandsberg <erik@heimdalldata.com> — 2024-12-08T17:06:43Z
Check the extension ph_cron, while I have never used it, it may be good to use as part of the solution. On Sun, Dec 8, 2024, 6:39 AM kunwar singh <krishsingh.111@gmail.com> wrote: > Hello Listers, > Looking for your inputs on the most efficient way to do it in Postgres. > > What I want to do: > === > I want to spawn 10 concurrent sessions each executing a complex stored > procedure with one of the parameters being the product ID. > Example > > CALL process_product(curdate, region, productid=>1) ; > CALL process_product(curdate, region, productid=>2) ; > CALL process_product(curdate, region, productid=>3) ; > CALL process_product(curdate, region, productid=>4) ; > ... > CALL process_product(curdate, region, productid=>10) ; > > > Say I get a list of product IDs by running a big query > > Product ID > ==== > 1 > 2 > 3 > 4 > .. > 10 > > > Additional Information > === > Everytime number of product ids will change. At a given time there should > be no more than 10 concurrent sessions of process_product. > I want to trigger these procedure calls once every hour. For a given hour > the number of product IDs could range from 10 to 100 in total. > I am using RDS Postgres v 15. > > Question > === > I know I can create a bash script or Python script , but I am wondering if > there is a smarter way to do it in Postgres? > > > > -- > Cheers, > Kunwar >