Method CrossJoin

src/jrd/optimizer/Optimizer.cpp:171–264

	{
	public:
		CrossJoin(Optimizer* opt, RiverList& rivers, JoinType joinType)
			: River(opt->getCompilerScratch(), nullptr, rivers)
		{
			fb_assert(joinType != OUTER_JOIN);

			const auto csb = opt->getCompilerScratch();
			Optimizer::ConjunctIterator iter(opt->getBaseConjuncts());

			// Save states of the underlying streams and restore them afterwards

			StreamStateHolder stateHolder(csb, m_streams);
			stateHolder.deactivate();

			// Generate record source objects

			const FB_SIZE_T riverCount = rivers.getCount();

			if (riverCount == 1)
			{
				const auto subRiver = rivers.pop();
				const auto subRsb = subRiver->getRecordSource();
				subRiver->activate(csb);
				m_rsb = opt->applyBoolean(subRsb, iter);
			}
			else
			{
				HalfStaticArray<RecordSource*, OPT_STATIC_ITEMS> rsbs(riverCount);

				if (joinType == INNER_JOIN)
				{
					// Reorder input rivers according to their possible inter-dependencies

					while (rivers.hasData())
					{
						const auto orgCount = rsbs.getCount();

						for (auto& subRiver : rivers)
						{
							subRiver->activate(csb);

							if (subRiver->isComputable(csb))
							{
								auto subRsb = subRiver->getRecordSource();
								subRsb = opt->applyBoolean(subRsb, iter);

								rsbs.add(subRsb);
								rivers.remove(&subRiver);
								break;
							}

							subRiver->deactivate(csb);
						}

						if (rsbs.getCount() == orgCount)
							break;
					}

					if (rivers.hasData())