oracle total recall

I wonder if anybody used this feature and what are Your impressions?

We turn it on lately on some application and here a little subjective first look:
- enabling it is easy - point A

• we add data - point B
• first "restore" of previous state was quite fast - point C, logical state from A
• then we do a little more changes - point D
• and flashback again - point E, logical state from C - this time it went really long (ie. few days), which puzzles me - it was 15 min. of changes and flashing them back was longer then creating the database from scratch (ie. import file)

We assumed this is a penalty for not purging total recall data when in C, so the next time I did it (ie. purging). This time it seems to run faster, but I may only dream about the performance of the first time (ie. C). Sure, the database is founded on some test environment, but not so bad, I dare to say, though storage is some RAID5, but still wonder...

I saw that flashback goes with db file sequential reads block by block, so it can not be too fast, but still wonder...

Did anybody notice such characteristic of that feature? Any clever tips or tricks to speed things up (and I do not mean a faster IO susbsystem, more memory and faster CPU, but rather suggestion for example to get rid of flashback archive after every flashback operation and enable it again or truncate somehow flashback archive system tables with drop storage option, because I have noticed the segments after purge are of the same size as before).
Of course there is always an option I did something wrong... (and this would be also good to know)

Best regards
Remigiusz

-- 
Pole nakazi

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Remigiusz Sokolowski <remigiusz.sokolowski_at_nordea.com>
pos   : DBA at DIiUSI
addr  : Nordea Bank Polska SA, Luzycka 6A Street, 81-537 Gdynia, Poland
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