Some time ago, we did a benchmark test in a DB box in non-RAC mode,
with ARCHIVELOG turned off. "IOStat by Filetype summary" in the AWR
reports shows 68G data written.
| Filetype Name | Writes: Data |
|---------------+--------------|
| Log File | 119.2G |
| Data File | 68.6G |
| Control File | 14M |
| Temp File | 1M |
|---------------+--------------|
| TOTAL: | 187.8G |
Recently we repeated the same test (with identical data setup) in a
new DB box in a two-node RAC configuration, with ARCHIVELOG turned on.
The AWR report shows a much bigger 185G data written.
| Filetype Name | Writes: Data |
|---------------+--------------|
| Log File | 128.1G |
| Data File | 184.8G |
| Archive Log | 128.3G |
| Control File | 105M |
| Temp File | 7M |
|---------------+--------------|
| TOTAL: | 441.3G |
We could not understand the data volume discrepancy. Aside from the
non-RAC vs RAC, NOARCHIVELOG vs ARCHIVELOG, we also noticed that
redundancy in ASM was set to MIRROR (2x) in the old box vs HIGH (3x)
in the new box.
ARCHIVELOG should have no impact on the data file volume. Could
either RAC or redundancy setting explain the volume difference?
Thank you.