Thanks Richard! So if we remove the remote machine and focus on the same host - running as a separate process based on System.Data.SQLite can I safely run a SELECT query without harming the database integrity or the 3rd party app writing to the database?
If so, is it a simple matter of executing the select from the same host, or do I need to set readonly on the System.Data.SQLite data connection or <other consideration>? Again - my goal is not to affect the existing database's internal settings. I truly appreciate your input! On Fri, Sep 4, 2015 at 11:24 AM, Richard Hipp <drh at sqlite.org> wrote: > WAL mode requires the use of shared memory (in this case implemented > using the mmapped -shm file) in order to coordinate access to the > write-ahead log by various processes doing access. But in order to > share memory, all processes accessing the database have to be on the > same machine, obviously. > > So, no, it is not possible to run a database in WAL mode on one > machine and simultaneously access that database over a network share > from another machine. You'll have to switch to one of the rollback > modes (ex: DELETE) in order to do that. > > On 9/4/15, Todd Biggins <tbiggins at gmail.com> wrote: > > Hello all, > > > > I've been digging through SQLite.org and these forums, but I was hoping > for > > a final consensus on my conundrum: > > > > I have a third party app that is writing to a local v3.0 SQLite database > > with WAL. I want to access it outside of the existing app solely for the > > purpose of SELECT queries (using System.Data.SQLite) - these queries > would > > be run by only one other process, either from the same host or a remote > > machine (by sharing the database folder through NTFS/SMB) > > > > Am I able to run SELECT queries without altering the database integrity > for > > the other app? Since the database is using WAL, it looks like I need > write > > access to the folder structure, and even a SELECT query attempts to > > generate the -WAL and -SHM file on the database - files which already > exist > > from the 3rd party app. > > > > To reiterate - is there a "safe" way to use System.Data.SQLite to > passively > > view tables without altering the database or its cache? > > > > Thanks so much for your time! > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users at mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > > > -- > D. Richard Hipp > drh at sqlite.org > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
