Subject | RE: [firebird-support] Backup file padding |
---|---|
Author | Robert Harris |
Post date | 2017-09-25T15:47:27Z |
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.
Regards,
Robert
Robert Harris
Chief Technical Officer
Zzyzxl Ltd.
Web: www.zzyzxl.com
email: robert@...
Main Office: 353 (0)45 864485
Support: 353 (0)45 864484
Cell: 353 (0)87 6676534
-----Original Message-----
From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com]
Sent: 25 September 2017 15:46
To: firebird-support@yahoogroups.com
Subject: [firebird-support] Backup file padding
Hello.
What is the purpose of backup file being padded by zeros up to 512 bytes
block?
--
WBR, SD.
------------------------------------
------------------------------------
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Visit http://www.firebirdsql.org and click the Documentation item on the
main (top) menu. Try FAQ and other links from the left-side menu there.
Also search the knowledgebases at
http://www.ibphoenix.com/resources/documents/
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
------------------------------------
Yahoo Groups Links
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.
Regards,
Robert
Robert Harris
Chief Technical Officer
Zzyzxl Ltd.
Web: www.zzyzxl.com
email: robert@...
Main Office: 353 (0)45 864485
Support: 353 (0)45 864484
Cell: 353 (0)87 6676534
-----Original Message-----
From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com]
Sent: 25 September 2017 15:46
To: firebird-support@yahoogroups.com
Subject: [firebird-support] Backup file padding
Hello.
What is the purpose of backup file being padded by zeros up to 512 bytes
block?
--
WBR, SD.
------------------------------------
------------------------------------
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Visit http://www.firebirdsql.org and click the Documentation item on the
main (top) menu. Try FAQ and other links from the left-side menu there.
Also search the knowledgebases at
http://www.ibphoenix.com/resources/documents/
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
------------------------------------
Yahoo Groups Links