On 03/16/2017 05:00 PM, Tomasz Maj wrote:
I have an application which work with many zipped databases in WAL journal mode 
and the databases are stored on a media of low write bandwidth. There is a 
problem that that fsync operations invoked from one thread are blocking other 
fsync operations invoked from another thread. I think that changing the 
synchronous mode to NORMAL on some connections may make the blocking issue less 
painful. May the possibility of changing ZIPVFS synchronous mode be implemented 
in sqlite?


Latest commit in the zipvfs project fixes things so that "PRAGMA synchronous" works with zipvfs databases.

Dan.





Cheers,

Tomasz M

________________________________
From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> on behalf of Tomek 
Maj <majek...@gmail.com>
Sent: Thursday, March 16, 2017 10:50:37 AM
To: SQLite mailing list
Subject: Re: [sqlite] Is it possible to change "synchronous" flag of ZIPVFS 
pager?

2017-03-16 9:51 GMT+01:00 Dan Kennedy <danielk1...@gmail.com>:

On 03/16/2017 01:40 PM, Tomasz Maj wrote:

Hi,


According to my observations, "PRAGMA synchronous=...;" query affects
only the standard sqlite pager. But for zipped databases sqlite uses
additional ZIPVFS pager layer which actually decide whether and when to
sync content of files associated with a database. It looks like "PRAGMA
synchronous=...;" query doesn't have any effect on zipped databases. Are my
observations right? If so, is it possible to manipulate "synchronous" flag
of ZIPVFS pager?

It looks like there is not. Is it something you need to do?

Dan.


_______________________________________________
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

_______________________________________________
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
_______________________________________________
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users


_______________________________________________
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

Reply via email to