5、页内通过tid获取记录需要在buf描述符content_lock的BUFFER_LOCK_SHARE内进行 6、调用heap_hot_search_buffer在对应buffer内通过tid获取对应heap记录,这里会遇到heap only tuple的情况: 1)通过tid得到heap的页号及记录索引号。如果进行update过,该tid是第一个打上delete标签的记录,而这个记录的t_ctid会指向新insert...
6、调用heap_hot_search_buffer在对应buffer内通过tid获取对应heap记录,这里会遇到heap only tuple的情况: 1)通过tid得到heap的页号及记录索引号。如果进行update过,该tid是第一个打上delete标签的记录,而这个记录的t_ctid会指向新insert的记录。 2)第一次进来,at_chain_start标记为TRUE即HOT链的起始记录 3)根据...
buffer while following a HOT link would prevent this type of problem, but checking XMIN/XMAX matching is a much more robust solution.) Index/Sequential Scans ---When doing an index scan, whenever we reach a HEAP_HOT_UPDATED tuple whose xmax is not aborted, we need to follow its t_ctid...
Profiler allocates 8kB perf_event buffer for each thread of the target process. Make sure /proc/sys/kernel/perf_event_mlock_kb value is large enough (more than 8 * threads) when running under unprivileged user. Otherwise the message "perf_event mmap failed: Operation not permitted" will be...
ExecStoreTuple(tup, slot, InvalidBuffer,false); d = slot_getattr(slot, BROKER_ATTR_HOST, &isnull); host = TextDatumGetCString(d); result = lappend(result, host); } ExecDropSingleTupleTableSlot(slot); heap_endscan(scan); heap_close(brokers, NoLock);returnresult; ...
ID3DBlob::GetBufferSize method (Windows) HTTP_REQUEST structure (Windows) EnumLanguageGroupsProc callback function (Windows) EnumTimeFormatsProc callback function (Windows) SecureZeroMemory function (Windows) WLAN_NOTIFICATION_DATA structure (Windows) ConnectionStatusHandler function (Windows) UserName (Wi...
一.堆的结构 堆为程序运行时主动申请的内存,通常称为堆区,操作堆的api从UserMode来看有: 例如malloc申请一块内存会先调用HeapCreate()为自己创建一块堆区. 堆区由不同大小的堆块组成,由堆表来索引所有堆块. 堆块由块首和块身构成,块首占8字节,由块大小和块计算单位和是否占用等信息,块身紧跟在块首,在提到...
假如所有处理函数都失败,调用进程级异常处理函数UEF(UnhandleExeceptionFilter),UEF会检测HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AeDebug下的UserDebuggerHotKey键值,假如为0,弹出错误消息对话框,提示是否打开调试器.若为1,则没有任何提示直接调用ExitProcess ...
Profiler allocates 8kB perf_event buffer for each thread of the target process. Make sure /proc/sys/kernel/perf_event_mlock_kb value is large enough (more than 8 * threads) when running under unprivileged user. Otherwise the message "perf_event mmap failed: Operation not permitted" will be...
(f) returning a page indicative of the unused slice, the page being a wrapped byte buffer that includes a reference to the slice where data is to be stored and a reference to an allocator object that created the slice; (g) continuing to return pages until the off-heap direct memory ...