Sizing Exadata - Oracle Exadata Recipes: A Problem-Solution Approach - page 133

(case
when upper('&&use_flashlog') like 'Y%' then (arch.gbpd)
else 0
end) flgb
from (
select
max((al.blks * kc.blksize)/1024/1024/1024) gbpd
from
(select
trunc(completion_time) dt,
sum(blocks) blks
from v$archived_log
group by trunc(completion_time)) al,
(select
max(lebsz) blksize
from x$kccle) kc
) arch,
(
select sum(bytes)/1024/1024/1024 dbgb
from v$datafile
) db,
(
select sum(bytes)/1024/1024/1024 redogb
from v$log
) redo
)
/
Enter value for num_days: 3
old 7: (arch.gbpd * &&num_days) ArchMaxReq,
new 7: (arch.gbpd * 3) ArchMaxReq,
Enter value for backups_to_exa: Y
old 9: when upper('&&backups_to_exa') like 'Y%' then (db.dbgb + arch.gbpd)
new 9: when upper('Y') like 'Y%' then (db.dbgb + arch.gbpd)
Enter value for use_flashlog: Y
old 13: when upper('&&use_flashlog') like 'Y%' then (arch.gbpd)
new 13: when upper('Y') like 'Y%' then (arch.gbpd)

DB OnlineLog ArchLog RMAN FlashLog
Req.(GB) Req.(GB) Req.(GB) Req.(GB) Req.(GB)) % for Data % for Reco/FRA
--------- ---------- ---------- --------- ---------- ----------- --------------
291.74 3.95 369.48 414.90 123.16 24.57 75.75

In the example above, we've chosen to perform RMAN backups to Exadata, store three days' worth of archived
redo logs on disk, and use Flashback features and retain one day of change on disk. Based on this database's change
rates, we arrive at a 25:75 split between storage requirements for database files and recovery-related files.

■ the logic presented in this recipe only considers a single database targeted for migration or deployment to
Exadata. You will need to follow a similar approach to properly size your consolidated database footprint. also, the script
calculates its percentages based on current database size and current rates of archived redo generation.

Note