Hello Lyall,
Explain Plan, Cost, disk reads, buffer gets, all line up pretty well in 11g
and 12c. The 2 things that are different is the actual time, slowest in 11g
is 2.5 seconds, 12c is 14 seconds. and percentage of work, 11g disk work is
85% and cpu work is 15%. 12c disk work is 98%, cpu 2%. Do i talk to the SAN
folks and see what their graphs are like? VM team? keep digging into AWR
stats and comparisons on the database?
Lyall Barbour <lyallbarbour@xxxxxxxxxxxxxxx> hat am 23. Juli 2019 um 18:39--
geschrieben:
Hello gurus,
We've upgraded and moved the company's CRM OLTP Oracle database.
Old: physical hardware, 512g RAM, 32 CPU -- Oracle 11.2.0.4 Enterprise, 16g
MEMORY_TARGET, SPM baselines used, one or two Profiles.
New: VMWare VM, 224g RAM, 24 vCPU -- Oracle 12.1.0.2 Enterprise, 72g
SGA_TARGET, HugePages, 12g PGA_TARGET, no SPM baselines, multiple Profiles.
Having said all that, there's a consistency to the slowness that's very
interesting. We are constantly having I/O waits on all (?) queries, if not
all, the main top sqls that are running in v$session_longops.
Comparing one query. Explain Plan, Cost, disk reads, buffer gets, all line
up pretty well in 11g and 12c. The 2 things that are different is the actual
time, slowest in 11g is 2.5 seconds, 12c is 14 seconds. and percentage of
work, 11g disk work is 85% and cpu work is 15%. 12c disk work is 98%, cpu
2%.
I'm not trying to get any solutions from everyone here, i'm trying to get
direction on where to look next so i know who to talk to at my company with
this issue. Do i talk to the SAN folks and see what their graphs are like?
VM team? keep digging into AWR stats and comparisons on the database?
Comparing AWR hour periods from today (oracle 12.1) to last week, tuesday,
(oracle 11.2) the amount of buffer gets and disk reads all line up with the
issue i described above. 420T of buffer cache reads last week, 10T today, in
that hour period. ALL work is waiting on disk.
Any help... helps.
Thanks,
Lyall Barbour