Yes, and why do you need to do that? (Use multiple connections to the same read only data)?
--- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. >-----Original Message----- >From: sqlite-users [mailto:sqlite-users- >boun...@mailinglists.sqlite.org] On Behalf Of Abrozy Nieprzelozy >Sent: Monday, 14 May, 2018 16:46 >To: SQLite mailing list >Subject: Re: [sqlite] Multi threaded readers on memory sqlite cannot >scale > >AFAIK the only way to access single memory database from multiple >connections >is through shared cache. > >2018-05-15 0:27 GMT+02:00, Keith Medcalf <kmedc...@dessus.com>: >> >>>2018-05-13 12:50 GMT+02:00, Techno Magos : >> >>>> Hello >> >>>> I do not have clear examples to post on this but would like to >>>> report findings around multi threaded read access (single >process) in a >>>> large system that uses sqlite. >> >>>> This may be a known issue/restriction of memory sqlite behaviour, >>>> but wanted to check with the list first: >> >>>> 1. Running 2, 3, ... 6 multi threaded readers of a single *memory >>>> *sqlite database (via shared cache mode) on an 8 core cpu shows >no >>>> throughput gain at all compared to single threaded throughput. >>>> In fact, it shows a throughput drop: i.e. if a single thread can >>>> do N simple queries/sec, 2 threads .. up to 6 threads do a little >>>> less (10% drop) in total. This suggests that access to memory >>>> sqlite can only be serialized? >> >> No one has asked the $10 million dollar question yet ... why are >you doing >> this? It certainly does not sound like you have a highly >constrained >> itty-bitty wee boxen for which the "shared cache" was designed (ie, >you seem >> to have more that 4 cycles per second of CPU and 10 bytes of >memory). >> >> So what was the configuration which you WERE PREVIOUSLY USING which >was >> deficient and for which you are trying this optimization? >> >> Everyone knows that when you use "shared cache mode" you are >trading off >> memory and CPU cycles against performance. Shared Cache Mode is >designed so >> that if you are *really* so inclined you can run SQLite on your >Tandy Pocket >> Computer too (https://en.wikipedia.org/wiki/Tandy_Pocket_Computer) >> >> --- >> The fact that there's a Highway to Hell but only a Stairway to >Heaven says a >> lot about anticipated traffic volume. >> >> >> >> >> _______________________________________________ >> 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
