Hi! >Понедельник, 28 декабря 2020, 15:13 +03:00 от Nikita Pettik : >  >On 28 Dec 11:54, Leonid Vasiliev wrote: >> Hi! >> >> On 24.12.2020 19:57, Nikita Pettik wrote: >> > On 11 Dec 18:29, Leonid Vasiliev wrote: >> > >> > IMHO before pushing performance aimed patches, we should carefully >> > review them. Could you run some SQL benchmarks to verify there's >> > no degradation on any case? >> >> Can you tell me where we have benchmarks for SQL and how to run them? > >We have tpc-h/tpc-c bench at least as I know: >https://github.com/tarantool/tpcc >https://github.com/tarantool/tpch > >Please contact QA team to get instructions how to lauch them. >    As I understood after conversation with Timur, Oleg can help me. So, I'll add him to the mailing list. Oleg, can you help me with the benchmarks?   >> > Also, does this change affect non-SQL >> > users? I mean does SQL tmp cache is lazy initialized or it allocates >> > all 20mb right on start? For sure, 18mb is not a lot memory in 2020, >> > but still it may turn out to be surprise for some users.. >> >> The memory allocation is done on per-request basis: >> "The default page cache implemention does not allocate the full amount >> of cache memory all at once. Cache memory is allocated in smaller chunks >> on an as-needed basis." > >Ok, fine, at least it won't affect users which don't use SQL sub-system. >So then we should only make sure that cache increase only improves >SQL performance on standard benches. > >> > > On 11.12.2020 15:09, Nikita Pettik wrote: >> > > > On 11 Dec 01:37, Leonid Vasiliev wrote: >> > > > > Increase the maximum number of in-memory pages to use >> > > > > for temporary tables. >> > > > > ( https://www.sqlite.org/compile.html#default_cache_size ) >> > > > > >> > > > > Part of #5609 >> > > > > --- >> > > > > >> > > > > Hi SQL team. It is a simplest part of #5609. >> > > > > This patch increases the default SQL cache size by 10 times to 20 MB. >> > > > > A similar experiment shows a 10% performance increase for some datasets. >> > > > > ( https://github.com/tarantool/tarantool/issues/5593#issuecomment-740044007 ). >> > > > > Mons approved these changes. I haven't done any research to determine the >> > > > > optimal value. So feel free to throw this patch away. >> > > > >> > > > Hi, why not inroduce separate handler for user to change this setting? >> > > > Since SQLite is embedded database, almost all settings are set at >> > > > compile time. In constrast, we can move it to the box. >> > > > >> > > >> > > If I understood you correctly, the settings should be implemented when >> > > working on # 5609 (this path doesn't close the task). This is the >> > > simplest improvement to update the default. >> > > >> > > > > https://github.com/tarantool/tarantool/issues/5609 >> > > > > https://github.com/tarantool/tarantool/tree/lvasiliev/gh-5609-increase-default-sql-sort-cache-size >> > > > > >> > > > > src/box/CMakeLists.txt | 4 ++++ >> > > > > 1 file changed, 4 insertions(+) >> > > > > >> > > > > diff --git a/src/box/CMakeLists.txt b/src/box/CMakeLists.txt >> > > > > index 19203f7..7372179 100644 >> > > > > --- a/src/box/CMakeLists.txt >> > > > > +++ b/src/box/CMakeLists.txt >> > > > > @@ -218,6 +218,10 @@ if(CMAKE_BUILD_TYPE STREQUAL "Debug") >> > > > > add_definitions(-DSQL_DEBUG=1) >> > > > > endif() >> > > > > add_definitions(-DSQL_TEST=1) >> > > > > +# Set the maximum number of in-memory pages to use for temporary tables. >> > > > > +# 20000 * 1024 = 20480000 bytes. >> > > > > +# ( https://www.sqlite.org/compile.html#default_cache_size ) >> > > > > +add_definitions(-DSQL_DEFAULT_CACHE_SIZE=-20000) >> > > > > set(EXT_SRC_DIR ${CMAKE_SOURCE_DIR}/extra) >> > > > > set(EXT_BIN_DIR ${CMAKE_BINARY_DIR}/extra) >> > > > > -- >> > > > > 2.7.4 >> > > > >     -- Leonid Vasiliev