Bugs fixed:
- MCOL-4649 CAST(double AS UNSIGNED) returns 0
- MCOL-4631 CAST(double AS SIGNED) returns 0 or NULL
- MCOL-4647 SEC_TO_TIME(double_or_float) returns a wrong result
Problems:
- The code in Func_cast_unsigned::getUintVal() and
Func_cast_signed::getIntVal() did not properly check
the double value to fit inside a uint64_t/int64_t range.
So the corner cases:
- numeric_limits<uint64_t>::max()-2 for uint64_t
- numeric_limits<int64_t>::max() for int64_t
produced unexpected results.
The problem was in tests like this:
if (value > (double) numeric_limits<int64_t>::max())
A correct test would be:
if (value >= (double) numeric_limits<int64_t>::max())
- The code in Func_sec_to_time::getStrVal() searched for the decimal
dot character, assuming that the next character after the dot
was the leftmost fractional digit.
This assumption was wrong because huge double numbers use
scientific notation. So for example in "2.5e-40" the
digit "5" following the dot is NOT the leftmost fractional digit.
Also, the code in Func_sec_to_time::getStrVal() was slow
because of using non necessary to-string and from-string
data conversion.
Also, the code in Func_sec_to_time::getStrVal() evaluated
the argument two times: using getStrVal() then using getIntVal().
Solution:
- Adding new classes TDouble and TLongDouble.
- Adding a few function templates to reuse the code easier.
- Moving the conversion code inside TDouble and TLongDouble
methods toMCSSInt64Round() and toMCSUInt64Round().
- Reusing new classes and their methods in func_cast.cc and
func_sec_to_time.cc.
This patch is fixing the following bugs:
- MCOL-4609 TreeNode::getIntVal() does not round: implicit DECIMAL->INT cast is not MariaDB compatible
- MCOL-4610 TreeNode::getUintVal() looses precision for narrow decimal
- MCOL-4619 TreeNode::getUintVal() does not round: Implicit DECIMAL->UINT conversion is not like in InnoDB
- MCOL-4650 TreeNode::getIntVal() looses precision for narrow decimal
- MCOL-4651 SEC_TO_TIME(hugePositiveDecimal) returns a negative time
The "SIGNED" part of the problem was previously fixed by MCOL-4640.
Fixing the "UNSIGNED" part.
- Adding TDecimal64::toUInt64Round() and Decimal::decimal64ToUInt64Round()
- Renaming Decimal::narrowRound() to decimal64ToSInt64Round(),
for a more self-descriptive name, and for symmetry with decimal64ToUInt64Round()
- Reusing TDecimal64::toSInt64Round() inside decimal64ToSInt64Round().
This change was forgotten in MCOL-4640 :(
- Removing the old code in Func_cast_unsigned::getUintVal with pow().
It caused precision loss, hence the bug. Adding a call for
Decimal::decimal64ToUInt64Round() instead.
- Adding tests for both SIGNED and UNSIGNED casts.
Additional change:
- Moving the wide-decimal-to-uint64_t rounding code from Func_cast_unsigned::getUintVal()
to TDecimal128::toUInt64Round() (with refactoring). Adding TDecimal::toUInt64Round()
for symmetry with TDecimal::toSInt64Round(). It will be easier to reuse the code
with way.
Detailed change list:
- Splitting out the narrow part of "class Decimal" into a separate class TDecimal64
- Adding a method TDecimal64::toSInt64Round()
- Reusing the method TDecimal64::toSInt64Round() in:
* Func_cast_signed::getIntVal()
* Func_char::getStrVal()
* Func_elt::getStrVal()
* makedate()
* Func_maketime::getStrVal()
Note, reusing this method in Func_char::getStrVal() also fixed this bug:
MCOL-4634 CHAR(negativeWideDecimal) is not like InnoDB
because the old code handled negative wide decimal values
in a wrong way.
- Adding a new class TDecimal128 for symmetry.
Moving a few wide decimal methods and constexpr's from Decimal to TDecimal128.
The new class TDecimal128 does not do much at this point yet.
Later we should be able to use TDecimal128 vs TDecimal64 in templates.
This change fixes:
MCOL-4462 CAST(varchar_expr AS DECIMAL(M,N)) returns a wrong result
MCOL-4500 Bit functions processing throws internally trying to cast char into decimal representation
MCOL-4532 CAST(AS DECIMAL) returns a garbage for large values
Also, this change makes string-to-decimal conversion 5-10 times faster,
depending on exact data.
Performance implemenent is achieved by the fact that (unlike in the old
implementation), the new version does not do any "string" object copying.
MCOL-4409 This patch combines VDecimal and Decimal and makes
IDB_Decimal an alias for the result class
MCOL-4409 More boilerplate reduction in Func_mod
Removed couple TSInt128::toType() methods
1. In TupleAggregateStep::configDeliveredRowGroup(), use
jobInfo.projectionCols instead of jobInfo.nonConstCols
for setting scale and precision if the source column is
wide decimal.
2. Tighten rules for wide decimal processing. Specifically:
a. Replace (precision > INT64MAXPRECISION) checks with
(precision > INT64MAXPRECISION && precision <= INT128MAXPRECISION)
b. At places where (colWidth == MAXDECIMALWIDTH) is not enough to
determine if a column is wide decimal or not, also add a check on
type being DECIMAL/UDECIMAL.
DOUBLE typecast was not supported and the failure detection caused a
crash.
This patch adds support for DOUBLE typecast and fixes the crash caused
when a non-supported function is detected as part of an arithmatic.
For the initial BLOB/TEXT pull request we put them in the same bucket as
VARBINARY, forcing many functions to be disabled. This patch enables the
same TEXT function support as VARCHAR.
