[Dev] Tizen 3.0 proposal for fixing OSP/WRT/Core hard-coded UID issue

Stéphane Desneux stephane.desneux at eurogiciel.fr
Thu Oct 17 17:07:52 GMT 2013


On 17/10/2013 11:50, Jussi Laako wrote:
> On 17.10.2013 12:31, Patrick Ohly wrote:
>> There's also nothing that prevents multithreading in such a design. I
>> don't see how you came to that conclusion. EDS is internally
>> multithreaded and allows concurrent reads directly from the sqlite file
>> (only writing is centralized).
>
> There's a write bottleneck, because with record-locking you could
> simultaneously write to different portions of file without conflicts.
> But unfortunately sqlite doesn't support that, so it needs some more
> advanced database.

Yes and no. It highly depends on how sqlite is compiled and used.

For example, tf the WAL mode is active, this could help to solve some 
access conflicts between readers and writers.

For more info:
http://www.sqlite.org/wal.html

in particular, "WAL provides more concurrency as readers do not block 
writers and a writer does not block readers. Reading and writing can 
proceed concurrently. "

 From what I saw, the WAL mode is not active actually on shared dbs. 
Instead, the rollback journal is forced to persist at compile time, 
probably to avoid ownership problems between the db and its journal.

-- 
Stéphane Desneux
Intel OTC - Vannes/FR


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