Sqlitediff diffs a same db (one db changed over time). If you are looking for diffing data using the same db scheme that has been generated at different times (producing different instances of the db scheme, eg you import data from somewhere and crate a same db scheme from it, but different instance therefore) you need your own tool. It is application specific.
Von meinem iPad gesendet > Am 19.11.2015 um 01:27 schrieb Nico Williams <nico at cryptonector.com>: > >> On Wed, Nov 18, 2015 at 11:56:50PM +0000, Simon Slavin wrote: >>> On 18 Nov 2015, at 10:58pm, Nico Williams <nico at cryptonector.com> wrote: >>> Can SQLite3 run the sub-queries of a UNION ALL with any degree of >>> concurrency? E.g., with its co-routines? >> >> SQLite always has the bottleneck of access to the file storage medium. >> Many posts to this list have complained that implementing >> multi-threading or multi-processing does not speed up SQLite >> significantly, and in some cases makes things worse. > > But two concurrent scans of the same table should be able to go faster > than the same two scans in series. > >> The problem here is not that SQLite does this job inefficiently, but >> that the job is a bit weird. If you know you're going to have to diff >> two versions of the same database, you have your program write a log >> of the modifications it makes. > > So weird that sqldiff exists. Huh. > > Writing a log is a nice idea that doesn't always work. There's no need > to go into that in detail. Suffice to say that a) I do use logs in some > case, b) diff'ing two tables is not such crazy thing to want to do. > > There's a whole class of problems that SQL query optimizers don't do as > well with as a programmer writing a general purpose programming language > can do. This is, IMO, an interesting problem. I'm not just after "how > can I do this faster", but "how can SQLite3 do this faster". I > understand and accept, of course, that the SQLite3 dev team may not be > interested in the latter. > > Thanks, > > Nico > -- > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
