Re: [sqlite] File Locking And Concurrency In SQLite Version 3
Hi, Thanks for the response. That is what I was planning to do, i.e. write some code that does the verification before I call sqlite3_open. However, I am not sure what code should I write. I mean the code I write to do the verification should be a representation of what sqlite3 does. Regards, Prakash Bande Altair Engg. Inc. Troy MI Ph: 248-614-2400 ext 489 Cell: 248-404-0292 -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Simon Slavin Sent: Friday, November 12, 2010 1:06 PM To: General Discussion of SQLite Database Subject: Re: [sqlite] File Locking And Concurrency In SQLite Version 3 On 12 Nov 2010, at 5:58pm, Prakash Reddy Bande wrote: > My question: Is it possible to verify if the network drive on which the DB is > place can be used? Great question. Unfortunately LockFile() generally does /not/ work. If you want to perform a check there are too many combinations of access methods and version numbers to use logic. I can only recommend you write some code that actually tries to do the locking and checks to see whether it worked. I have an application which does something similar in a Unix setup. It requires that the user runs two test applications at the same time -- either on the same computer or on two different computers. Simon. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] File Locking And Concurrency In SQLite Version 3
On 12 Nov 2010, at 5:58pm, Prakash Reddy Bande wrote: > My question: Is it possible to verify if the network drive on which the DB is > place can be used? Great question. Unfortunately LockFile() generally does /not/ work. If you want to perform a check there are too many combinations of access methods and version numbers to use logic. I can only recommend you write some code that actually tries to do the locking and checks to see whether it worked. I have an application which does something similar in a Unix setup. It requires that the user runs two test applications at the same time -- either on the same computer or on two different computers. Simon. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] File Locking And Concurrency In SQLite Version 3
Hello, I want to use sqlite as a db on a shared network drive (windows) (user would map the network drive to say T:). I read the documentation section "File Locking And Concurrency In SQLite Version 3" (http://www.sqlite.org/lockingv3.html) Where following is clearly mentioned: "SQLite uses POSIX advisory locks to implement locking on Unix. On Windows it uses the LockFile(), LockFileEx(), and UnlockFile() system calls. SQLite assumes that these system calls all work as advertised. If that is not the case, then database corruption can result. One should note that POSIX advisory locking is known to be buggy or even unimplemented on many NFS implementations (including recent versions of Mac OS X) and that there are reports of locking problems for network filesystems under Windows. Your best defense is to not use SQLite for files on a network filesystem." My question: Is it possible to verify if the network drive on which the DB is place can be used? What I would like to do is when user tries to load the db (sqlite3_open) first run the verification and inform the user that database is placed on a drive that does not support the locking mechanism required by our product. I am using sqlite-3.7.2 Regards, Prakash Bande Altair Engg. Inc. Troy MI Ph: 248-614-2400 ext 489 Cell: 248-404-0292 ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
