On 2021-05-29 09:25, Adrian Klaver wrote:
On 5/28/21 5:38 PM, Dean Gibson (DB Administrator) wrote:
Can you repeat your EXPLAIN (ANALYZE, BUFFERS) of the query from your first post and post them here:
https://explain.depesz.com/
Other information:
1) A diff of your configuration settings between 9.6 and 13.2.
2) Are you running on the same AWS instance type for the two versions of Postgres?
It is not necessary to repeat the table/view definitions as they are available in the first post.
Done.
1.There's probably about a hundred, but almost all are differences in the default values. The most interesting (from my point of view) is my setting work_mem in 8000 on v9.6, & 16000 (after 8000 didn't help) on v13. Doing a compare right now between the DEFAULT parameters for 9.6 & 13, RDS reports 93 differences in the default parameters between the two.
2. For v13, I moved from db.t2.micro to db.t3.micro, because RDS required that for v13. However, for the v10, 11, 12 upgrades, I kept db.t2.micro.
Meanwhile, I've been doing some checking. If I remove "CAST( license_status AS CHAR ) = 'A'", the problem disappears. Changing the JOIN to a RIGHT JOIN, & replacing WHERE with ON, also "solves" the problem, but there is an extra row where license_status is NULL, due to the RIGHT JOIN. Currently trying to figure that out (why did the CAST ... match 'A', if it is null?)...