Description:
The ndbassert:
ndbassert(useStat.m_scanFragReqCount > 0);
is faulty
The m_scanFragReqCount is a union with m_fragCopyRowIns that tracks
the number of rows inserted during the Copy fragment process.
This variable is set to 0 by the signal COPY_ACTIVEREQ after completing
the copy fragment process for the fragment. Coming here we should have
increased m_scanFragReqCount after receiving SCAN_FRAGREQ, however a
COPY_ACTIVEREQ arriving after SCAN_FRAGREQ will set this variable to 0.
Normally this behaviour would never happen since COPY_ACTIVEREQ is
sent long before the fragment is allowed to be used for scans.
However scans on ordered index actually uses the table distribution
of the primary table. This table is usually handled before the
ordered index table. Thus COPY_ACTIVEREQ on an ordered index table
could see a value of 0 in the execution of a SCAN_NEXTREQ or
CONTINUEB signal. But for the base table it should never be 0.
How to repeat:
daily-basic--10 in Autotest
Suggested fix:
#if defined(VM_TRACE) || defined(ERROR_INSERT)
TablerecPtr tablePtr;
tablePtr.i = regTcPtr->tableref;
ptrCheckGuard(tablePtr, ctabrecFileSize, tablerec);
ndbassert(useStat.m_scanFragReqCount > 0 ||
DictTabInfo::isOrderedIndex(tablePtr.p->tableType));
#endif
The faulty ndbassert is found in 3 places in DblqhMain.cpp
Description: The ndbassert: ndbassert(useStat.m_scanFragReqCount > 0); is faulty The m_scanFragReqCount is a union with m_fragCopyRowIns that tracks the number of rows inserted during the Copy fragment process. This variable is set to 0 by the signal COPY_ACTIVEREQ after completing the copy fragment process for the fragment. Coming here we should have increased m_scanFragReqCount after receiving SCAN_FRAGREQ, however a COPY_ACTIVEREQ arriving after SCAN_FRAGREQ will set this variable to 0. Normally this behaviour would never happen since COPY_ACTIVEREQ is sent long before the fragment is allowed to be used for scans. However scans on ordered index actually uses the table distribution of the primary table. This table is usually handled before the ordered index table. Thus COPY_ACTIVEREQ on an ordered index table could see a value of 0 in the execution of a SCAN_NEXTREQ or CONTINUEB signal. But for the base table it should never be 0. How to repeat: daily-basic--10 in Autotest Suggested fix: #if defined(VM_TRACE) || defined(ERROR_INSERT) TablerecPtr tablePtr; tablePtr.i = regTcPtr->tableref; ptrCheckGuard(tablePtr, ctabrecFileSize, tablerec); ndbassert(useStat.m_scanFragReqCount > 0 || DictTabInfo::isOrderedIndex(tablePtr.p->tableType)); #endif The faulty ndbassert is found in 3 places in DblqhMain.cpp