This patch:
1. Properly processes situation when pm join result count is exceeded.
2. Adds session variable 'columnstore_max_pm_join_result_count` to control the limit.
Added logical transformation of the execplan::ParseTrees with the taking out the common factor in expression of the form "(A and B) or (A and C)" for the purposes of passing a TPCH 19 query.
Co-authored-by: Leonid Fedorov <leonid.fedorov@mariadb.com>
When a UNION operation involving DECIMAL datatypes with scale and digits
before the decimal exceeds the currently supported maximum precision
of 38, we throw an error to the user:
"MCS-2060: Union operation exceeds maximum DECIMAL precision of 38".
This is until MCOL-5417 is implemented where ColumnStore will have
full parity with MariaDB server in terms of maximum supported DECIMAL
precision and scale of 65 and 38 digits respectively.
CSC default ctor was private b/c it must not allow to use CSC outside thread cache.
However there are some places in the plugin code that need a standalone syscat that
is cleaned up leaving the scope. The decision is to make the restriction mentioned
organizational rather than syntactical.
The following functions are created:
Create function JSON_VALID and test cases
Create function JSON_DEPTH and test cases
Create function JSON_LENGTH and test cases
Create function JSON_EQUALS and test cases
Create function JSON_NORMALIZE and test cases
Create function JSON_TYPE and test cases
Create function JSON_OBJECT and test cases
Create function JSON_ARRAY and test cases
Create function JSON_KEYS and test cases
Create function JSON_EXISTS and test cases
Create function JSON_QUOTE/JSON_UNQUOTE and test cases
Create function JSON_COMPACT/DETAILED/LOOSE and test cases
Create function JSON_MERGE and test cases
Create function JSON_MERGE_PATCH and test cases
Create function JSON_VALUE and test cases
Create function JSON_QUERY and test cases
Create function JSON_CONTAINS and test cases
Create function JSON_ARRAY_APPEND and test cases
Create function JSON_ARRAY_INSERT and test cases
Create function JSON_INSERT/REPLACE/SET and test cases
Create function JSON_REMOVE and test cases
Create function JSON_CONTAINS_PATH and test cases
Create function JSON_OVERLAPS and test cases
Create function JSON_EXTRACT and test cases
Create function JSON_SEARCH and test cases
Note:
Some functions output differs from MDB because session variables that affects functions output,e.g JSON_QUOTE/JSON_UNQUOTE
This depends on MCOL-5212
This function iterates over lbidList (populated by an earlier call to
DBRM::getUncommittedExtentLBIDs()) to find those LBIDs which belong to
the AUX column. It then finds the corresponding LBIDs for all other columns
which belong to the same table as the AUX LBID and appends them to lbidList.
The updated lbidList is used by invalidateUncommittedExtentLBIDs() to update
the casual partitioning information.
DBRM::addToLBIDList() only comes into play in case of a transaction ROLLBACK.
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
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.
After an AggreateColumn corresponding to SUM(1+1) is created,
it is pushed to the list:
gwi.count_asterisk_list.push_back(ac)
Later, in getSelectPlan(), the expression SUM(1+1) was erroneously
treated as a constant:
if (!hasNonSupportItem && !nonConstFunc(ifp) && !(parseInfo & AF_BIT) && tmpVec.size() == 0)
{
srcp.reset(buildReturnedColumn(item, gwi, gwi.fatalParseError));
This code freed the original AggregateColumn and replaced to a ConstantColumn.
But gwi.count_asterisk_list still pointer to the freed AggregateColumn().
The expression SUM(1+1) was treated as a constant because tmpVec
was empty due to a bug in this code:
// special handling for count(*). This should not be treated as constant.
if (isp->argument_count() == 1 &&
( sfitempp[0]->type() == Item::CONST_ITEM &&
(sfitempp[0]->cmp_type() == INT_RESULT ||
sfitempp[0]->cmp_type() == STRING_RESULT ||
sfitempp[0]->cmp_type() == REAL_RESULT ||
sfitempp[0]->cmp_type() == DECIMAL_RESULT)
)
)
{
field_vec.push_back((Item_field*)item); //dummy
Notice, it handles only aggregate functions with explicit literals
passed as an argument, while it does not handle constant expressions
such as 1+1.
Fix:
- Adding new classes ConstantColumnNull, ConstantColumnString,
ConstantColumnNum, ConstantColumnUInt, ConstantColumnSInt,
ConstantColumnReal, ValStrStdString, to reuse the code easier.
- Moving a part of the code from the case branch handling CONST_ITEM
in buildReturnedColumn() into a new function
newConstantColumnNotNullUsingValNativeNoTz(). This
makes the code easier to read and to reuse in the future.
- Adding a new function newConstantColumnMaybeNullFromValStrNoTz().
Removing dulplicate code from !!!four!!! places, using the new
function instead.
- Adding a function isSupportedAggregateWithOneConstArg() to
properly catch all constant expressions. Using the new function parse_item()
in the code commented as "special handling for count(*)".
Now it pushes all constant expressions to field_vec, not only
explicit literals.
- Moving a part of the code from buildAggregateColumn()
to a helper function processAggregateColumnConstArg().
Using processAggregateColumnConstArg() in the CONST_ITEM
and NULL_ITEM branches.
- Adding a new branch in buildReturnedColumn() handling FUNC_ITEM.
If a function has constant arguments, a ConstantColumn() is
immediately created, without going to
buildArithmeticColumn()/buildFunctionColumn().
- Reusing isSupportedAggregateWithOneConstArg()
and processAggregateColumnConstArg() in buildAggregateColumn().
A new branch catches aggregate function has only one constant argument
and immediately creates a single ConstantColumn without
traversing to the argument sub-components.
When an outer query filter accesses an subquery column that contains an aggregate or a window function, certain optimizations can't be performed. We had been looking at the surface of the returned column. We now iterate into any functions or operations looking for aggregates and window functions.
mcsconfig.h and my_config.h have the following
pre-processor definitions:
1. Conflicting definitions coming from the standard cmake definitions:
- PACKAGE
- PACKAGE_BUGREPORT
- PACKAGE_NAME
- PACKAGE_STRING
- PACKAGE_TARNAME
- PACKAGE_VERSION
- VERSION
2. Conflicting definitions of other kinds:
- HAVE_STRTOLL - this is a dirt in MariaDB headers.
Should be fixed in the server code. my_config.h erroneously
performs "#define HAVE_STRTOLL" instead of "#define HAVE_STRTOLL 1".
in some cases. The former is not CMake compatible style. The latter is.
3. Non-conflicting definitions:
Otherwise, mcsconfig.h and my_config.h should be mutually compatible,
because both are generated by cmake on the same host machine. So
they should have exactly equal definitions like "HAVE_XXX", "SIZEOF_XXX", etc.
Observations:
- It's OK to include both mcsconfig.h and my_config.h providing that we
suppress duplicate definition of the above conflicting types #1 and #2.
- There is no a need to suppress duplicate definitions mentioned in #3,
as they are compatible!
- my_sys.h and m_ctype.h must always follow a CMake configuation header,
either my_config.h or mcsconfig.h (or both).
They must never be included without any preceeding configuration header.
This change make sure that we resolve conflicts by:
- either disallowing inclusion of mcsconfig.h and my_config.h
at the same time
- or by hiding conflicting definitions #1 and #2
(with their later restoring).
- also, by making sure that my_sys.h and m_ctype.h always follow
a CMake configuration file.
Details:
- idb_mysql.h can now only be included only after my_config.h
An attempt to use idb_mysql.h with mcsconfig.h instead of
my_config.h is caught by the "#error" preprocessor directive.
- mariadb_my_sys.h can now be only included after mcsconfig.h.
An attempt to use mariadb_my_sys.h without mcscofig.h
(e.g. with my_config.h) is also caught by "#error".
- collation.h now can now be included in two ways.
It now has the following effective structure:
#if defined(PREFER_MY_CONFIG_H) && defined(MY_CONFIG_H)
// Remember current conflicting definitions on the preprocessor stack
// Undefine current conflicting definitions
#endif
#include "mcsconfig.h"
#include "m_ctype.h"
#if defined(PREFER_MY_CONFIG_H) && defined(MY_CONFIG_H)
# Restore conflicting definitions from the preprocessor stack
#endif
and can be included as follows:
a. using only mcsconfig.h as a configuration header:
// my_config.h must not be included so far
#include "collation.h"
b. using my_config.h as the first included configuration file:
#define PREFER_MY_CONFIG_H // Force conflict resolution
#include "my_config.h" // can be included directly or indirectly
...
#include "collation.h"
Other changes:
- Adding helper header files
utils/common/mcsconfig_conflicting_defs_remember.h
utils/common/mcsconfig_conflicting_defs_restore.h
utils/common/mcsconfig_conflicting_defs_undef.h
to perform conflict resolution easier.
- Removing `#include "collation.h"` from a number of files,
as it's automatically included from rowgroup.h.
- Removing redundant `#include "utils_utf8.h"`.
This change is not directly related to the problem being fixed,
but it's nice to remove redundant directives for both collation.h
and utils_utf8.h from all the files that do not really need them.
(this change could probably have gone as a separate commit)
- Changing my_init() to MY_INIT(argv[0]) in the MCS services sources.
After the fix of the complitation failure it appeared that ColumnStore
services compiled with the debug build crash due to recent changes in
safemalloc. The crash happened in strcmp() with `my_progname` as an argument
(where my_progname is a mysys global variable). This problem should
probably be fixed on the server side as well to avoid passing NULL.
But, the majority of MariaDB executable programs also use MY_INIT(argv[0])
rather than my_init(). So let's make MCS do like the other programs do.