Block Compression Fundamental for Restore Process

Backup Archive and Restore (BAR)
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Enthusiast

Block Compression Fundamental for Restore Process

Suppose you backup/archieve a database in production and restore it in test with block compression enabled.

While restoring/copying to test database server, how come the disk size of current permanent is greater by the time the restore is completed?

Is it because the process is compressing backup (production)>uncompress in test>recompress in test?


Accepted Solutions
Teradata Employee

Re: Block Compression Fundamental for Restore Process

The observed PermSpace is likely to be different (not necessarily larger) when copying to another platform because the rows must be redistributed across the AMPs, and block compression efficiency depends (among other things) on data distribution and blocksize. 

1 ACCEPTED SOLUTION
3 REPLIES 3
Enthusiast

Re: Block Compression Fundamental for Restore Process

Anyone please?

Teradata Employee

Re: Block Compression Fundamental for Restore Process

The observed PermSpace is likely to be different (not necessarily larger) when copying to another platform because the rows must be redistributed across the AMPs, and block compression efficiency depends (among other things) on data distribution and blocksize. 

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Enthusiast

Re: Block Compression Fundamental for Restore Process

Aha. That clearly explains it. Thank you