Additionally, to prevent early wearout of your persistent storage, make sure to configure SQLite, such that temporary files are stored in RAM rather than Flash. Compile with SQLITE_TEMP_STORE=3 or use PRAGMA temp_store (https://www.sqlite.org/tempfiles.html). In an embedded system, you should prefer the compiler switch. Furthermore, you like to tune SQLite's page cache and other memory optimization parameters to adapt SQLite to your constrained memory resources. At least, consider to use UBIFS over JFFS2 if possible. SQLite in normal journaling mode and UBIFS on NAND-Flash is fast and very reliable, even in cases of sudden power loss during transactions.
______________________________________ Carsten Stelling F&E Hardware / R&D Hardware G?RLITZ Aktiengesellschaft | August-Thyssen-Stra?e 32 | D-56070 Koblenz T: +49-261-9285-336 | M: | F: +49-261-9285-190 Mail to: Carsten.Stelling at goerlitz.com | www.goerlitz.com Vorstand | Executive Board: J?rg Figge Vorsitzender des Aufsichtsrates | Chairman of the supervisory board: Norbert Wagner Registergericht | Court of registration: Amtsgericht Koblenz HRB 5346 Sitz der Gesellschaft | Registered office: Koblenz Sind Sie bereit f?r das Schl?sselerlebnis? www.goerlitz.com/e-world-2016 Member of the IDS-Group -----Urspr?ngliche Nachricht----- Von: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users-bounces at mailinglists.sqlite.org] Im Auftrag von David Woodhouse Gesendet: Dienstag, 5. Januar 2016 23:50 An: Ward WIllats; General Discussion of SQLite Database Betreff: Re: [sqlite] Caveats using Sqlite on JFFS2 ? On Mon, 2016-01-04 at 13:17 -0800, Ward WIllats wrote: > Happy New Year folks. > > Subject says it all. Any things to look out for when using Sqlite on > a JFFS2 filesystem? I see some old stuff from 2011 about WAL mode and > MMAP_SHARED, but suspect that is no longer germane? Anything else to > watch out for? (This would be for an Open-WRT style embedded Linux on > MIPS.) JFFS2 still doesn't support shared writeable mmap; that kind of thing is discouraged on flash. But other than that, there should be nothing that's really specific to JFFS2. You want to avoid doing too many writes, obviously, but that's true for *all* flash-based storage, even the ones which are pretending to be spinning rust and hiding the details from the OS. -- David Woodhouse Open Source Technology Centre David.Woodhouse at intel.com Intel Corporation
