Re: [PERFORM] Very poor read performance, query independent

2017-08-18 Thread Mark Kirkwood
Nice! Pleased that the general idea worked well for you! I'm also relieved that you did not follow my recommendation exactly - I'm been trialling a Samsung 960 Evo (256GB) and Intel 600p (256GB) and I've stumbled across the serious disadvantages of (consumer) M.2 drives using TLC NAND - terri

Re: [PERFORM] Odd sudden performance degradation related to temp object churn

2017-08-18 Thread Mark Kirkwood
On 19/08/17 02:21, Jeremy Finzel wrote: On Tue, Aug 15, 2017 at 12:07 PM, Scott Marlowe mailto:scott.marl...@gmail.com>> wrote: So do iostat or iotop show you if / where your disks are working hardest? Or is this CPU overhead that's killing performance? Sorry for the delayed reply.

[PERFORM] Query plan for views and WHERE clauses, Luke is not using the index

2017-08-18 Thread kimaidou
Hi all, I have come across a unexpected behavior. You can see full detail on an issue on the QGEP project in Github : https://github.com/QGEP/QGEP/issues/308#issuecomment-323122514 Basically, we have this view with some LEFT JOIN : http://paste.debian.net/982003/ We have indexes on some fields (

Re: [PERFORM] Odd sudden performance degradation related to temp object churn

2017-08-18 Thread Jeremy Finzel
On Tue, Aug 15, 2017 at 12:07 PM, Scott Marlowe wrote: > So do iostat or iotop show you if / where your disks are working > hardest? Or is this CPU overhead that's killing performance? > Sorry for the delayed reply. I took a look in more detail at the query plans from our problem query during t