[sqlite] The Lock-Byte Page

2015-12-28 Thread Dan Kennedy
On 12/28/2015 05:08 AM, Olivier Mascia wrote: > Hello, > > I'm referring to paragraph 1.3 of https://www.sqlite.org/fileformat2.html > about the Lock-Byte page. > > From what I read, I understand those 2^9 bytes at offset 2^30, should they > exist, are set aside, untouched by SQLite nor the

[sqlite] The Lock-Byte Page

2015-12-28 Thread Olivier Mascia
> Le 28 d?c. 2015 ? 08:27, Dan Kennedy a ?crit : > > It's because (at least historically - may have changed?) win32 does not > support advisory locks. So if you take an EXCLUSIVE lock on a range of bytes > no other process can read them. This is different from Unix, where all locks > are

[sqlite] The Lock-Byte Page

2015-12-27 Thread Olivier Mascia
> Le 27 d?c. 2015 ? 23:17, Simon Slavin a ?crit : > > These bytes can be used by a VFS designed to run on those operating systems > to allow communication between processes about lock status. Thanks a lot for the whole explanation Simon. Much clearer now. -- Meilleures salutations, Met

[sqlite] The Lock-Byte Page

2015-12-27 Thread Olivier Mascia
Hello, I'm referring to paragraph 1.3 of https://www.sqlite.org/fileformat2.html about the Lock-Byte page.

[sqlite] The Lock-Byte Page

2015-12-27 Thread Simon Slavin
On 27 Dec 2015, at 10:08pm, Olivier Mascia wrote: > What I don't really get straight is what file-locking related mechanism would > have a use for those bytes, knowing they wouldn't even exists unless the > database size is 2^30 bytes or more? Some operating systems for unusual operating