Method init

src/jrd/recsrc/HashJoin.cpp:277–364

}

void HashJoin::init(thread_db* tdbb, CompilerScratch* csb, FB_SIZE_T count,
					RecordSource* const* args, NestValueArray* const* keys,
					double selectivity)
{
	m_impure = csb->allocImpure<Impure>();

	m_leader.source = args[0];
	m_leader.keys = keys[0];
	const FB_SIZE_T leaderKeyCount = m_leader.keys->getCount();
	m_leader.keyLengths = FB_NEW_POOL(csb->csb_pool) ULONG[leaderKeyCount];
	m_leader.totalKeyLength = 0;

	m_cardinality = m_leader.source->getCardinality();

	for (FB_SIZE_T j = 0; j < leaderKeyCount; j++)
	{
		dsc desc;
		(*m_leader.keys)[j]->getDesc(tdbb, csb, &desc);

		USHORT keyLength = desc.isText() ? desc.getStringLength() : desc.dsc_length;

		if (IS_INTL_DATA(&desc))
			keyLength = INTL_key_length(tdbb, INTL_INDEX_TYPE(&desc), keyLength);
		else if (desc.isTime())
			keyLength = sizeof(ISC_TIME);
		else if (desc.isTimeStamp())
			keyLength = sizeof(ISC_TIMESTAMP);
		else if (desc.dsc_dtype == dtype_dec64)
			keyLength = Decimal64::getKeyLength();
		else if (desc.dsc_dtype == dtype_dec128)
			keyLength = Decimal128::getKeyLength();

		m_leader.keyLengths[j] = keyLength;
		m_leader.totalKeyLength += keyLength;
	}

	auto keyCount = 0;

	for (FB_SIZE_T i = 1; i < count; i++)
	{
		RecordSource* const sub_rsb = args[i];
		fb_assert(sub_rsb);

		m_cardinality *= sub_rsb->getCardinality();

		SubStream sub;
		sub.buffer = FB_NEW_POOL(csb->csb_pool) BufferedStream(csb, sub_rsb);
		sub.keys = keys[i];
		const FB_SIZE_T subKeyCount = sub.keys->getCount();
		sub.keyLengths = FB_NEW_POOL(csb->csb_pool) ULONG[subKeyCount];
		sub.totalKeyLength = 0;

		keyCount += subKeyCount;

		for (FB_SIZE_T j = 0; j < subKeyCount; j++)
		{
			dsc desc;
			(*sub.keys)[j]->getDesc(tdbb, csb, &desc);