On 17 Feb 2016, at 3:34pm, Simon Slavin <slavins at bigfraud.org> wrote:
> A lot of operations on the database file are done at the beginning and end of > every transaction. If your journal is in memory, then you can dramatically > disk usage by using large transactions. So I think you are right and you > should check out that strategy. I'm sorry, that's poorly phrased and has a word missing. Here's a better version: A high proportion of the disk activity involved in making changes to the database are done to support the transaction structure, rather than the individual operation (INSERT/UPDATE/DELETE) you asked for. Grouping lots of operations together into one transaction will reduce the overhead needed for locking and ACID. In addition, in some journal modes operations relating to the transaction as a whole are done with the database file whereas much of the work relating to the operations is done with the journal file. This should increase the advantage in your situation gained by using large transactions. Simon.
