Subject RE: [firebird-support] Backup file padding
Author Robert Harris
Hi Dimitry,
Cannot be 100% certain but 512 bytes was typically the sector size of hard
drives when gbak was written. Each sector contains only a single packet of
data, be-it 1 byte or 512 bytes. Reading/Writing data with the size of a
sector typically offers much better performance in terms of speed. Much the
same as memory alignment within an application. Also, writing pages of a
variable length means that internally a chain has to be managed, much like a
linked list, with pages of a known size chunks of data can be read using
single C fread statements which specify the block size.



Robert Harris
Chief Technical Officer
Zzyzxl Ltd.

email: robert@...

Main Office: 353 (0)45 864485
Support: 353 (0)45 864484
Cell: 353 (0)87 6676534


-----Original Message-----
Sent: 25 September 2017 15:46
Subject: [firebird-support] Backup file padding


What is the purpose of backup file being padded by zeros up to 512 bytes





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