ah ok, now I understand. So you would like some setting like "limit writes to x/s", keeping the intermediate writes in memory.
Here is a great writeup on how to tune sqlite for writes: https://stackoverflow.com/q/1711631/124416 But depending on your app you might just group a ton of writes in a single transaction and retain all the regular safeties. E.g. suppose you have an incoming stream of messages to write, you could group them and confirm receipt of each message after the transaction completes. On Tue, Apr 10, 2018, 10:43 AM Pavel Cernohorsky, < pavel.cernohor...@appeartv.com> wrote: > I understand that the SQLite tells the OS all the correct things, but as > I described earlier, that may just produce way too much IOPS, even if > everything in the chain does the correct thing down to the last silicon > transistor. That is why I was asking about a way how to go around it by > holding part of the newest data in memory only and manually checkpoint > (and I hoped WAL will be a way). And I got some very good suggestions > earlier. > > In my last mail, I have outlined a calculation suggesting the SSD may > wear out pretty soon with the described load. Yesterday I have found a > way how not to speculate and get some real data - Samsung's Enterprise > SSDs which we use provide a diagnostics which measures a real world load > and using their drive's SMART capabilities calculates the estimated > SSD's lifetime, in other words saying how bad the load really is. It is > actually a very useful thing, so if somebody else needs it as well, here > is the link: > > https://www.slideshare.net/SamsungBusinessUSA/using-smart-attributes-to-estimate-enterprise-ssd-lifetime > > Pavel > > > > On 04/09/2018 02:47 PM, Simon Slavin wrote: > > On 9 Apr 2018, at 8:41am, Pavel Cernohorsky < > pavel.cernohor...@appeartv.com> wrote: > > > >> if you use bigger pro-level SSD, you get on a bit less that 1 year.. > still not good enough. Of course, big unknown in this is the constant > representing the ability of the SSD controller to merge requests and > minimize block re-writes. > > If you compiled SQLite with standard options, and have the correct > settings for > > > > PRAGMA fullfsync (Macintosh only) > > PRAGMA journal_mode > > PRAGMA synchronous > > > > then SQLite tells the operating system all the correct things. > > > > Whether the operating system, the storage driver, and the storage > subsystem itself do the right things is out of control of software. Not > only can you not tell what's being done, but it can change with what looks > like a minor change in driver or hardware. > > > > Simon. > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users@mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
