This patch improves handling of NULLs in textual fields in ColumnStore.
Previously empty strings were considered NULLs and it could be a problem
if data scheme allows for empty strings. It was also one of major
reasons of behavior difference between ColumnStore and other engines in
MariaDB family.
Also, this patch fixes some other bugs and incorrect behavior, for
example, incorrect comparison for "column <= ''" which evaluates to
constant True for all purposes before this patch.
This patch fixes a wrong `join id` assignment for `TupleHashJoinStep` in a view.
After MCOL-334 CS assigns a '-1' as `join id` for `TupleHashJoinStep` in a view, and
in this case we cannot apply a filter for specific `Join step`, which is associated with `join id`
for 2 reasons:
1. Filters for all `TupleHashJoinSteps` associated with the same `join id`, which is '-1'.
2. When CS creates a `joinIdIndexMap` it eliminates all `join ids` which a less or equal 0.
This patch also fixes some tests for the view, which were generated wrong results.
* 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* Fix ISO C++17 does not allow 'register' storage class specifier for outdated bison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
Part 1:
As part of MCOL-3776 to address synchronization issue while accessing
the fTimeZone member of the Func class, mutex locks were added to the
accessor and mutator methods. However, this slows down processing
of TIMESTAMP columns in PrimProc significantly as all threads across
all concurrently running queries would serialize on the mutex. This
is because PrimProc only has a single global object for the functor
class (class derived from Func in utils/funcexp/functor.h) for a given
function name. To fix this problem:
(1) We remove the fTimeZone as a member of the Func derived classes
(hence removing the mutexes) and instead use the fOperationType
member of the FunctionColumn class to propagate the timezone values
down to the individual functor processing functions such as
FunctionColumn::getStrVal(), FunctionColumn::getIntVal(), etc.
(2) To achieve (1), a timezone member is added to the
execplan::CalpontSystemCatalog::ColType class.
Part 2:
Several functors in the Funcexp code call dataconvert::gmtSecToMySQLTime()
and dataconvert::mySQLTimeToGmtSec() functions for conversion between seconds
since unix epoch and broken-down representation. These functions in turn call
the C library function localtime_r() which currently has a known bug of holding
a global lock via a call to __tz_convert. This significantly reduces performance
in multi-threaded applications where multiple threads concurrently call
localtime_r(). More details on the bug:
https://sourceware.org/bugzilla/show_bug.cgi?id=16145
This bug in localtime_r() caused processing of the Functors in PrimProc to
slowdown significantly since a query execution causes Functors code to be
processed in a multi-threaded manner.
As a fix, we remove the calls to localtime_r() from gmtSecToMySQLTime()
and mySQLTimeToGmtSec() by performing the timezone-to-offset conversion
(done in dataconvert::timeZoneToOffset()) during the execution plan
creation in the plugin. Note that localtime_r() is only called when the
time_zone system variable is set to "SYSTEM".
This fix also required changing the timezone type from a std::string to
a long across the system.
2. Set Decimal precision in SimpleColumn::evaluate().
3. Add support for int128_t in ConstantColumn.
4. Set IDB_Decimal::s128Value in buildDecimalColumn().
5. Use width 16 as first if predicate for branching based on decimal width.
Replaced BINARYEMPTYROW and BINARYNULL values. We need to have
separate magic values for numeric and non-numeric binary types
b/c numeric cant tolerate losing 0 used for magics previously.
atoi128() now parses minus sign and produces negative values.
RowAggregation::isNull() now uses Row::isNull() for DECIMAL.
There are multiple overloaded version of the low level DML write methods to
push down CSC column type. WE needs the type to convert values correctly.
Replaced WE_INT128 with CSC data type that is more informative.
Removed commented and obsolete code.
Replaced switch-case blocks with oneliners.
simpleScalarFilterToParseTree() performs a dynamic allocation
of a ParseTree object, but this memory is never freed later.
We now keep track of this allocation and perform the delete
in ~CSEP/CSEP::unserialize() after the query finishes.
simpleScalarFilterToParseTree() performs a dynamic allocation
of a ParseTree object, but this memory is never freed later.
We now keep track of this allocation and perform the delete
in the JobList dtor after the query finishes.
This appears to be to fix equality matches in InfiniDB but at the same
time it breaks LIKE processing. Equality matching with trailing
whitespace was fixed in MCOL-1246 so the old InfiniDB patch can be
removed.
