operations + morsel size weight model to equally allocate CPU b/w parallel query morsels.
This patch delivers better parallel query timings distribution(timings graph resembles normal
distribution with a bigger left side thus more queries runs faster comparing with PrioThreadPool-based
single-node installation).
See changes in batchprimitiveprocessor-jl.h and comments in fair_threadpool.h for
important implementation details
* MCOL-4560 remove unused xml entries and code that references it.
There is reader code and variables for some of these settings, but nobody uses them.
EM and PP are most resource-hungry runtimes.
The merge enables to control their cummulative
resource consumption, thread allocation + enables
zero-copy data exchange b/w local EM and PP facilities.
Short CHAR/VARCHAR column values contain integer-encoded strings.
After certain manipulations(orderSwap(strnxfrm(str))) the values
become integers that preserve original strings order relation
according to a certain translation rules(collation). Prepared
values are ready to be SIMD-processed.
respondWait could be set to false
while other threads were waiting. With respondWait false, okToRrespond
wouldn't ever get notify_one(). Get rid of respondWait and use
fProcessorPool->blockedThreadCount to determine if any threads may be
waiting.
The idea is relatively simple - encode prefixes of collated strings as
integers and use them to compute extents' ranges. Then we can eliminate
extents with strings.
The actual patch does have all the code there but miss one important
step: we do not keep collation index, we keep charset index. Because of
this, some of the tests in the bugfix suite fail and thus main
functionality is turned off.
The reason of this patch to be put into PR at all is that it contains
changes that made CHAR/VARCHAR columns unsigned. This change is needed in
vectorization work.
* Fix clang warnings
* Remove vim tab guides
* initialize variables
* 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length
* Fix ISO C++17 does not allow 'register' storage class specifier for outdated bison
* chars are unsigned on ARM, having if (ival < 0) always false
* chars are unsigned by default on ARM and comparison with -1 if always true
data types TEXT, CHAR, VARCHAR, FLOAT and DOUBLE are not yet supported by vectorized path
This patch introduces an example for Google benchmarking suite to measure a perf diff
b/w legacy scan/filtering code and the templated version
SCommand StrFilterCmd::duplicate() missed these two lines:
filterCmd->leftColType = leftColType;
filterCmd->rightColType = rightColType;
which exist in the parent's FilterCommand::duplicate().
Rewriting the code to avoid duplication by using more inherited
methods/constructors. This reduces the probability of similar bugs
in the future.
