[sqlite] Query takes 8 seconds on one machine but I abort after 40+ minutes on other machines

[Simon Slavin]

On 27 Jul 2015, at 1:44pm, rotaiv <rotaiv at gmail.com> wrote:

> SELECT home.fpath
> FROM home
> LEFT JOIN work ON work.fpath = home.fpath
> WHERE work.fpath IS NULL
> AND home.ftype = 'f?;

Are you sure you got this right ?  It uses work.fpath twice:

> LEFT JOIN work ON work.fpath = home.fpath
> WHERE work.fpath IS NULL

So you're checking both to see that [work.fpath = home.fpath ] and to see that 
[work.fpath IS NULL].  This looks weird to me.

Simon.