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Archives of the TeradataForum
Message Posted: Fri, 09 Nov 2001 @ 15:35:10 GMT
| Subj: | | Re: Rehash on a restore |
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| From: | | Dieter N�th |
| | I'm looking for someone who has some experience with doing restores after a hardware upgrade. | |
Don't ask me ;-)
| | Last year we did an upgrade that required a sysint (you think I'd be good t them by now). My restores took about the same
amount of time as my archives, but were running on a machine 3 times faster (1 node to 3 nodes). | |
| | The restores from the last upgrade had messages as follows: | |
| | *** Warning 3803:Table 'B_MB_DETAIL' already exists.
NEED TO RE-HASH ROWS
STARTING TO RESTORE TABLE "HBCADM"."B_MB_DETAIL" | |
| | I would have expected the same kind of message restoring from one system to another - after all they have a different hash
map. | |
A different hash map, but the same hashing algorithm. When you SYSINITed, you probably used the new Universal Hash, so all rowhashes had
to be recalculated.
When you restore to a system with different AMPs, then the rowhashes stay the same, the rows are only redistributed across all AMP.
Dieter
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