> On Dec 31, 2018, at 1:49 PM, Simon Slavin <slav...@bigfraud.org> wrote: > > If you have a 100 Gig table with no indexes suited to your clauses, creating > a temporary index might take a minute or two. But you really only have > yourself to blame. […] > Since the one possibly-long operation happens at the very beginning of the > command, and it can be long only if you're a bad SQL programmer, it's > unlikely that your timeout will happen during it.
Or the storage medium the database is on might be slow (like an SD card or a CD-ROM). Or the OS might be under severe I/O pressure, and all disk reads might be taking orders of magnitude longer than usual. (I’ve seen this happen shortly after startup on macOS, when there are many background OS tasks doing housekeeping as well as multiple user applications relaunching. Although this was back in the days of hard drives and may be less of an issue now with SSDs.) I daresay it’s also possible that an application might need to run a query that SQLite is incapable of optimizing sufficiently to avoid table scans. —Jens _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
