db and storage snapshot - may be a little OFF-TOPIC

we support test env creation partially by making snapshots on the storage array level. One of the nice sides of this are storage savings. The algorithm behind snapshot is simple - modification of the snapshot copies modified block content to snapshot storage and modifies it there, while source stays intact.

We found few cases where the storage designated for snapshot modification become equal to the snapshot source, which means every resource block modified - all of them Oracle databases. Are You able to name a database operation, which would modify every block in database (or assuming this is about array blocks (in this case 256k) one per every 32 blocks)?

Of course there are no operations like database restore and no visible pattern despite the fact that only Oracle databases are prone to it (but I would not say this is 100% sure). The array is IBM Storwize. The db is 11.2. The OS is Linux flavour.

I appreciate the slightest hypothesis, thanks in advance

Best regards
Remigiusz

-- 
Pole na kazi

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Remigiusz Sokolowski <remigiusz.sokolowski_at_nordea.com>
pos   : Senior DBA at DIiUSI
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