This changes the files table to use normalisation for the names and
versions. The idea is that these are often common between all remote
devices, and repeating an integer is more efficient than repeating a
long string. A new benchmark bears this out; for a database with 100k
files shared between 31 devices, with some worst case assumption on
version vector size, the database is reduced in size by 50% and the test
finishes quicker:
Current:
db_bench_test.go:322: Total size: 6263.70 MiB
--- PASS: TestBenchmarkSizeManyFilesRemotes (1084.89s)
New:
db_bench_test.go:326: Total size: 3049.95 MiB
--- PASS: TestBenchmarkSizeManyFilesRemotes (776.97s)
The other benchmarks end up about the same within the margin of
variability, with one possible exception being that RemoteNeed seems to
be a little slower on average:
old files/s new files/s
Update/n=RemoteNeed/size=1000-8 5.051k 4.654k
Update/n=RemoteNeed/size=2000-8 5.201k 4.384k
Update/n=RemoteNeed/size=4000-8 4.943k 4.242k
Update/n=RemoteNeed/size=8000-8 5.099k 3.527k
Update/n=RemoteNeed/size=16000-8 3.686k 3.847k
Update/n=RemoteNeed/size=30000-8 4.456k 3.482k
I'm not sure why, possibly that query can be optimised anyhow.
Signed-off-by: Jakob Borg <jakob@kastelo.net>
No practical effect, just a tiny bit of fun to stamp the database files
with an application ID that identifies them.
Signed-off-by: Jakob Borg <jakob@kastelo.net>
This reduces database migration memory usage in my test scenario from
3.8 GB to 440 MB. In principle I don't think we're causing many temp
tables to be generated anyway in normal usage, but if we do and someone
can benchmark a performance difference, we can add a tunable. I ran the
database benchmark before and after and didn't see a difference above
the noise level.
Signed-off-by: Jakob Borg <jakob@kastelo.net>
This changes the database structure to use one database per folder, with
a small main database to coordinate. Reverts the prior change to buffer
all files in memory when pulling, meaning there is now a phase where the
WAL file will grow significantly, at least for initial sync of folders
with many directories.
---------
Co-authored-by: bt90 <btom1990@googlemail.com>
