50 to 100% slower
From: niall.litchfield@xxxxxxxxx <niall.litchfield@xxxxxxxxx>
Sent: Monday, August 22, 2022 11:28 AM
To: Beckstrom, Jeffrey <jbeckstrom@xxxxxxxxx>
Cc: oracle-l@xxxxxxxxxxxxx
Subject: [EXTERNAL] Re: rman backup slow even after patching it
What does "slow" mean in this context?
On Mon, Aug 15, 2022 at 6:37 PM Beckstrom, Jeffrey
<jbeckstrom@xxxxxxxxx<mailto:jbeckstrom@xxxxxxxxx>> wrote:
In 19.14, rman backup significantly slower than in 11g. This morning I put on
some RMAN patches to no effect. In the rman trace file from a running backup I
see:
Adjusting buffer count to honor available PGA; old bufcnt: 4, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Adjusting buffer count to honor available PGA; old bufcnt: 4, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Adjusting buffer count to honor available PGA; old bufcnt: 5, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Adjusting buffer count to honor available PGA; old bufcnt: 6, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Adjusting buffer count to honor available PGA; old bufcnt: 4, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Adjusting buffer count to honor available PGA; old bufcnt: 5, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Adjusting buffer count to honor available PGA; old bufcnt: 8, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Adjusting buffer count to honor available PGA; old bufcnt: 16, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 892876434, pga_available: 0
Backup envisage an unusual situation due to PGA memory availability: we are
using only 2 read threads (instead of 9) for the current backup session
Adjusting buffer count to honor available PGA; old bufcnt: 4, new bufcnt: 2,
pga_agg_limit: 0, pga_agg_target: 0, pga_agg_used: 913692181, pga_available: 0
Pga_aggregate targe is set at the cdb to a value. At the pdb level it is 0.
Pga_aggregate_limit is not set anywhere.
Do I need to set the pga_aggregate limit?
Do I need to set both parameters at the PDB level?
Jeffrey Beckstrom
Greater Cleveland Regional Transit Authority
1240 W. 6th Street
Cleveland, Ohio 44113
--
Niall Litchfield
Oracle DBA
http://www.orawin.info<https://gcc02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.orawin.info%2F&data=05%7C01%7Cjbeckstrom%40gcrta.org%7C8813fde787fb4d451d2f08da8452e8cd%7Cebe8e20736ec47f48cb8f5f757605f5d%7C1%7C0%7C637967788883820894%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=IKQn%2F6Dm3%2FMbOtiO%2FxjL3ZNZhrDOu0PXG3FDyZEq%2BSY%3D&reserved=0>
