Date: Wed, 27 May 2020 21:26:00 +0000 From: bugzilla-noreply@freebsd.org To: ports-bugs@FreeBSD.org Subject: [Bug 241385] databases/sqlite3: enable OS features Message-ID: <bug-241385-7788-sCTosiq7bq@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-241385-7788@https.bugs.freebsd.org/bugzilla/> References: <bug-241385-7788@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D241385 Thomas Munro <tmunro@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |tmunro@FreeBSD.org --- Comment #12 from Thomas Munro <tmunro@FreeBSD.org> --- "The operating system must have a unified buffer cache in order for the memory-mapped I/O extension to work correctly, especially in situations whe= re two processes are accessing the same database file and one process is using memory-mapped I/O while the other is not. Not all operating systems have a unified buffer cache. In some operating systems that claim to have a unified buffer cache, the implementation is buggy and can lead to corrupt databases= ." Note that FreeBSD with ZFS doesn't have a unified buffer cache (mmap'd files are duplicated in the ARC and regular kernel buffers). I don't know whether it's safe or not or how the performance compares to pwrite/pread, for sqlit= e3.=20 Also, I noticed that other distributions like Debian are not enabling the m= map option, and are going with pread/pwrite despite their unified buffer cache. --=20 You are receiving this mail because: You are the assignee for the bug.=
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