Re: [suse-oracle] MD5 sums or archives differ between productionandstandby

I just checked our 10.2.0.4 database and am seeing what you see. None of
the archive log md5 checksums match on production and physical standbys.
On our 9.2.0.7 databases they do match.

> I thought that dataguard just ships the archives unchanged on 
> the standby and 
> then applies them.  
Apparently not anymore.

> Does it change the file content during 
> transmission?
Obviously.

Apparently the logs are different in 10g. Why? I don't know. I'd guess
it has something to do with time stamping when the files have arrived
and whether they've been applied to the standby database. Might have
something to do with RMAN functionality too.

I did a hexdump on two applied log files and the differences between
them are quite small. Most of it looks like one byte flags or possibly
timestamps. Here's the diff.
[oracle@junk]$ hexdump 1_3730_627648241.dbf.primary > hexdump.primary
[oracle@junk]$ hexdump 1_3730_627648241.dbf.standby > hexdump.standby
[oracle@junk]$ diff hexdump.primary hexdump.standby
6c6
< 0000200 2201 0000 0001 0000 0e92 0000 8000 c323
---
> 0000200 2201 0000 0001 0000 0e92 0000 8000 e0bf
8c8
< 0000220 0042 0000 cf9b 0005 9000 0001 0200 0000
---
> 0000220 0042 0000 cf0f 0005 9000 0001 0200 0000
16c16
< 00002a0 26f1 2569 0001 0000 0000 0000 0002 0000
---
> 00002a0 26f1 2569 0001 0000 0000 0000 0001 0000
20c20
< 00002e0 020e 0000 a7b0 2812 0000 0000 0011 0000
---
> 00002e0 020e 0000 a7b0 2812 0000 0000 20c1 0000
22,23c22
< 0000300 0000 0000 0000 0000 0000 0000 03db 0000
< 0000310 0000 0000 0000 0000 0000 0000 0000 0000
---
> 0000300 0000 0000 0000 0000 0000 0000 0000 0000
That's not very much different for a 50mb file.

I'd say if you are really concerned open up an SR on metalink.

> -----Original Message-----
snip
> Silviu Marin-Caea
> Sent: Thursday, December 04, 2008 2:21 AM
snip
> We have 10gR2 10.2.0.3
> 
> I can't find not even one archive that is identical between 
> production and 
> standby.  I have run md5sum --check on all of them.
> 
snip
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