Re: [sqlite] Attached databases and union view.

2019-08-22 Thread Peter da Silva
to Heaven says > a lot about anticipated traffic volume. > > >-Original Message- > >From: sqlite-users [mailto:sqlite-users- > >boun...@mailinglists.sqlite.org] On Behalf Of Peter da Silva > >Sent: Thursday, 22 August, 2019 11:57 > >To: SQLite mailing list &g

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread Keith Medcalf
nticipated traffic volume. >-Original Message- >From: sqlite-users [mailto:sqlite-users- >boun...@mailinglists.sqlite.org] On Behalf Of Peter da Silva >Sent: Thursday, 22 August, 2019 11:57 >To: SQLite mailing list >Subject: Re: [sqlite] Attached databases and union view. &

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread Peter da Silva
Still a bit over 3x slower on queries but that's a 7x performance improvement. On Thu, Aug 22, 2019 at 11:40 AM Peter da Silva wrote: > Legit. I'll try that. > > On Thu, Aug 22, 2019 at 11:33 AM David Raymond > wrote: > >> I don't know how smart the planner is, but as a thought, would UNION

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread Peter da Silva
Originally Tcl/native Tcl binding, now a C++ extension calling the C-binding that's a Tcl extension itself. On Thu, Aug 22, 2019 at 11:17 AM test user wrote: > What language/binding library are you using? > > On Thu, 22 Aug 2019 at 16:45, Peter da Silva wrote: > > > Database is on tmpfs and

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread Peter da Silva
Legit. I'll try that. On Thu, Aug 22, 2019 at 11:33 AM David Raymond wrote: > I don't know how smart the planner is, but as a thought, would UNION ALL > make any improvement over just UNION? With just UNION it has to > de-duplicate all the subquery results whereas with UNION ALL it would be >

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread David Raymond
I don't know how smart the planner is, but as a thought, would UNION ALL make any improvement over just UNION? With just UNION it has to de-duplicate all the subquery results whereas with UNION ALL it would be free to separate all the various subqueries from each other. Or do you actually need

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread test user
What language/binding library are you using? On Thu, 22 Aug 2019 at 16:45, Peter da Silva wrote: > Database is on tmpfs and periodically snapshotted to SSD. There are > bottlenecks upstream of sqlite that we can see in traces. > > On Thu, Aug 22, 2019 at 10:36 AM Warren Young wrote: > > > On

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread Peter da Silva
Database is on tmpfs and periodically snapshotted to SSD. There are bottlenecks upstream of sqlite that we can see in traces. On Thu, Aug 22, 2019 at 10:36 AM Warren Young wrote: > On Aug 22, 2019, at 9:27 AM, Peter da Silva wrote: > > > > Have an existing application that's pushing the limit

Re: [sqlite] Attached databases and union view.

2019-08-22 Thread Warren Young
On Aug 22, 2019, at 9:27 AM, Peter da Silva wrote: > > Have an existing application that's pushing the limit If the limit is in hardware, shards won’t help. For example, a SQLite DB on a 7200 RPM spinning disk is limited to about 60 transactions per second under the stock SQLite fsync logic,

RE: [sqlite] attached databases

2007-07-04 Thread Samuel R. Neff
Use UNION to run queries against each db and return a single result. HTH, Sam --- We're Hiring! Seeking a passionate developer to join our team building products. Position is in the Washington D.C. metro area. If interested contact [EMAIL PROTECTED]

Re: [sqlite] Attached databases & locking

2005-06-23 Thread D. Richard Hipp
On Thu, 2005-06-23 at 14:50 -0700, Tim McDaniel wrote: > Question... > > Two database files, say A & B. > Open A. > Attach B. > Write to a table in A. > Write to a table in B. > > During the writes, is the file not being written to locked? > No locks are taken on unused databases. -- D.