There are multiple programs working in parallel. 750 of them from several compute nodes.
I use command line sqlite3, so, sqlite itself it not a suspect. FLoM is like a file lock: flom argumentsToFLoMIncludingTimeout -- sqlite3 "sqlStatement;" I am using linux, I think this analyzer is windows only. There several things that can fail: FLoM mismanaged locks is my primary suspect. But I would think database would be corrupt, not empty. Maybe I should ask a different question: Would knowing answer to my question (is it possible for DB to become empty?) help me single out FLoM as the cause of the problem? Roman ________________________________________ From: sqlite-users [sqlite-users-boun...@mailinglists.sqlite.org] on behalf of Simon Slavin [slav...@bigfraud.org] Sent: Thursday, November 07, 2019 7:28 PM To: SQLite mailing list Subject: Re: [sqlite] database is empty but intact On 8 Nov 2019, at 12:03am, Roman Fleysher <roman.fleys...@einstein.yu.edu> wrote: > I am using command line sqlite3 with -vfs unix-none. This disables locking > within SQLite. Instead, locking is provided externally by FLoM (distributed > file lock manager). I asked questions in a thread "disable file locking > mechanism over the network". Is SQLite telling FLoM when it should place or remove a lock ? If not, how does FLoM know ? Do you have more than one process which might write to the database ? Do all your processes which write to the database close their connections correctly ? Do they check the result codes from their calls to see if SQlite successfully closed the database ? > It is possible that FLoM has bugs and mismanaged locks. As a result, the > database is now empty. PRAGMA integrity check shows the database is intact. I > would expect it to be corrupt. The only DELETE operation in the queries was > to delete a single row: > > DELETE FROM jobs WHERE rowID = XXX; > > Could this DELETE actually delete entire content of a table if lock is > mismanaged? It could, though it is unsual. Have you run the analysis program on the file to find out more about it ? <https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsqlite.org%2Fsqlanalyze.html&data=02%7C01%7Croman.fleysher%40einstein.yu.edu%7C885cd07bd2e8437eb7df08d763e29b88%7C04c70eb48f2648079934e02e89266ad0%7C1%7C0%7C637087697235291714&sdata=Yq0C78yBQevXalcqKywwxOSV69EeRYLAG0755lCoMMY%3D&reserved=0> It could allow you to distinguish between a table with no rows in, and a table with lots of deleted rows in. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailinglists.sqlite.org%2Fcgi-bin%2Fmailman%2Flistinfo%2Fsqlite-users&data=02%7C01%7Croman.fleysher%40einstein.yu.edu%7C885cd07bd2e8437eb7df08d763e29b88%7C04c70eb48f2648079934e02e89266ad0%7C1%7C0%7C637087697235291714&sdata=kCZumJpJuTsUpSw4wl2XncG7aATqbPFqDpaXXFc9ecs%3D&reserved=0 _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
