问题 (std::bad_alloc） 通过 QThread 中的 QSqlQuery 将大图像(约 36 MB）保存到

我在尝试保存相对较大(~36 mb)的图像时遇到QSqlQuery问题。当我调用QSqlQuery：：exec()时，我得到std：：bad_alloc exeption。当我处理较小的图像时，一切都很好。 需要说的是 - 此代码在QThread的其他实例中执行，以防止GUI冻结，所有代码均在MinGW-32编译器中编译，PC上有8 GB RAM。有时(很少)即使使用这种大小的图像(36 mb)，我也会运行此代码而没有此异常

这是代码：

......
QByteArray byte_array_image, byte_array_icon;
QBuffer buffer_image(&byte_array_image), buffer_icon(&byte_array_icon);
buffer_image.open(QIODevice::WriteOnly);
buffer_icon.open(QIODevice::WriteOnly);
image->save(&buffer_image, format.toLocal8Bit().data());
icon->save(&buffer_icon, "JPEG");
query.prepare("INSERT INTO pictures (id, id_act, date_time, name, picture, icon) VALUES (:id, :id_act, :date_time, :name, :picture, :icon)");
......
query.bindValue(":picture", byte_array_image);
query.bindValue(":icon", byte_array_icon);
byte_array_image.clear();
byte_array_icon.clear();
save_succeed = query.exec();
if (!save_succeed)
emit database_failed(QUERY_ERROR_HEADER, QUERY_ERROR_SAVE_IMAGE + query.lastError().text());
emit query_finished();
return save_succeed; 

据我所知，问题可能与QApplication创建QString实例的堆空间不足有关，包括图像的所有字节码。为了解决这个问题，我试图将此图像分成十个部分，但这无济于事。

下面是由十个部分拆分的查询代码：

............
QByteArray byte_array_image, byte_array_icon;
QBuffer buffer_image(&byte_array_image), buffer_icon(&byte_array_icon);
buffer_image.open(QIODevice::WriteOnly);
buffer_icon.open(QIODevice::WriteOnly);
image->save(&buffer_image, format.toLocal8Bit().data());
icon->save(&buffer_icon, "JPEG");
int partlen, parts_count = 0;
save_succeed = false;
while (!save_succeed && ++parts_count < 10)
{
partlen = byte_array_image.size();
partlen = byte_array_image.size() / parts_count;
query.clear();
query.prepare("INSERT INTO pictures (id, id_act, date_time, name, part_one, parts_count, icon, src, src_act) "
"VALUES (:id, :id_act, :date_time, :name, :part_one, :parts_count, :icon, :src, :src_act)");
........
query.bindValue(":part_one", byte_array_image.mid(0, partlen));
query.bindValue(":parts_count", parts_count);
query.bindValue(":icon", byte_array_icon);
try
{
save_succeed = query.exec();
}
catch (std::bad_alloc &error)
{
if (parts_count < 10)
continue;
emit database_failed(QUERY_HEAP_ERROR_HEADER, QUERY_HEAP_ERROR_TEXT);
return false;
}
}
if (save_succeed)
{
QStringList part_names = { "part_one", "part_two", "part_three", "part_four", "part_five",
"part_six", "part_seven", "part_eight", "part_nine", "part_ten"};
for (int current_part = 1; current_part < parts_count; ++current_part)
{
query.clear();
query.prepare("UPDATE pictures SET "+part_names[current_part]+" = :current_part WHERE id = :id AND src = :src");
query.bindValue(":current_part", current_part == parts_count - 1 ? byte_array_image.mid(current_part*partlen) : byte_array_image.mid(current_part*partlen, partlen));
........
save_succeed = query.exec();
}
}
byte_array_image.clear();
byte_array_icon.clear();

我对问题来源是否正确？我能做些什么来修复它吗？图像的36 MB并不多。