$ clickhouse-benchmark -i 10000 -d 0 --parallelize_output_from_storages=0 -q "select * from values('foo')"
Loaded 1 queries.
Queries executed: 10000.
localhost:9000, queries 10000, QPS: 2800.490, RPS: 2800.490, MiB/s: 0.032, result RPS: 2800.490, result MiB/s: 0.032.
0.000% 0.000 sec.
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90.000% 0.000 sec.
95.000% 0.000 sec.
99.000% 0.001 sec.
99.900% 0.001 sec.
99.990% 0.001 sec.
$ clickhouse-benchmark -i 10000 -d 0 --parallelize_output_from_storages=1 -q "select * from values('foo')"
Loaded 1 queries.
Queries executed: 10000.
localhost:9000, queries 10000, QPS: 1259.805, RPS: 1259.805, MiB/s: 0.014, result RPS: 1259.805, result MiB/s: 0.014.
0.000% 0.001 sec.
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30.000% 0.001 sec.
40.000% 0.001 sec.
50.000% 0.001 sec.
60.000% 0.001 sec.
70.000% 0.001 sec.
80.000% 0.001 sec.
90.000% 0.001 sec.
95.000% 0.001 sec.
99.000% 0.001 sec.
99.900% 0.001 sec.
99.990% 0.003 sec.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
- lots of static_cast
- add safe_cast
- types adjustments
- config
- IStorage::read/watch
- ...
- some TODO's (to convert types in future)
P.S. That was quite a journey...
v2: fixes after rebase
v3: fix conflicts after #42308 merged
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
The original motivation for this commit was that shared_ptr_helper used
std::shared_ptr<>() which does two heap allocations instead of
make_shared<>() which does a single allocation. Turned out that
1. the affected code (--> Storages/) is not on a hot path (rendering the
performance argument moot ...)
2. yet copying Storage objects is potentially dangerous and was
previously allowed.
Hence, this change
- removes shared_ptr_helper and as a result all inherited create() methods,
- instead, Storage objects are now created using make_shared<>() by the
caller (for that to work, many constructors had to be made public), and
- all Storage classes were marked as noncopyable using boost::noncopyable.
In sum, we are (likely) not making things faster but the code becomes
cleaner and harder to misuse.
