Re: CPU hogged by concurrent SELECT..FOR UPDATE SKIP LOCKED

2020-08-24 Thread Jeff Janes
On Tue, Aug 18, 2020 at 8:22 PM Jim Jarvie wrote: > I've tuned the LIMIT value both up and down. As I move the limit up, the > problem becomes substantially worse; 300 swamps it and the selects take > 1 > hour to complete; at 600 they just all lock everything up and it stops > processing. I did

Re: sizing / capacity planning tipps related to expected request or transactions per second

2020-08-24 Thread Pavel Stehule
Hi po 24. 8. 2020 v 18:40 odesílatel Dirk Krautschick < dirk.krautsch...@trivadis.com> napsal: > Hi, > > are there any nice rules of thumb about capacity planning in relation the > expected > amount of transactions or request per second? > > For example, if I have around 100 000 transactions per

Re: sizing / capacity planning tipps related to expected request or transactions per second

2020-08-24 Thread MichaelDBA
Hi Dirk, There are a bunch of other things to consider besides just TPS and size of database.  Since PG is process-bound, I would consider connection activity: How many active connections at any one time?  This greatly affects your CPUs.  SQL workload is another big factor: a lot of complex q

sizing / capacity planning tipps related to expected request or transactions per second

2020-08-24 Thread Dirk Krautschick
Hi, are there any nice rules of thumb about capacity planning in relation the expected amount of transactions or request per second? For example, if I have around 100 000 transactions per second on a 5 TB database. With what amount of Memory and CPUs/Cores and which settings would you basically