James K. Lowden wrote: > On Sat, 19 Jan 2019 08:07:42 -0500 Richard Hipp <d...@sqlite.org> wrote: >> The busy timeout is not working because you start out your transaction >> using a read operation - the first SELECT statement - which gets a read >> lock. Later when you go to COMMIT, this has to elevate to a write >> lock. But SQLite sees that some other process has already updated the >> database since you started your read. > > Another solution is to rely on atomicity in SQL: > > insert into t > select :pid, nrows, N > from (select 1 as N union select 2 union select 3) as cardinals > cross join (select :pid, count(*) as nrows from t) as how_many; > > By using a single SQL statement, you avoid a user-defined transaction > and any proprietary transaction qualifiers.
Thank you for the suggestion, but I don't believe this is an option in my application. There's too much back-and-forth between the database and my logic to put it all into a single statement. Thus, transactions are necessary. Transactions exist to allow multiple statements to become an atomic unit, so eschewing them is basically the same thing as admitting they don't work. There are two possibilities: 1. Transactions do work, but I'm misusing them and must learn how to be more careful. In this case, I will update documentation to properly explain their use to others. 2. Transactions don't work, at least not for my task. In this case, I will do my best to investigate the problem and suggest a correction. Either way, the right thing for me to do is continue digging in. Going from BEGIN to BEGIN IMMEDIATE indeed fixed the test program I wrote, but my application is still broken, and I don't know what's different about it. I'm working on instrumenting the fcntl() calls to log the sequence of operations. ------------------------------------------- CONFIDENTIALITY NOTICE: This email and any attachments are for the sole use of the intended recipient and may contain material that is proprietary, confidential, privileged or otherwise legally protected or restricted under applicable government laws. Any review, disclosure, distributing or other use without expressed permission of the sender is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies without reading, printing, or saving.. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
