Function BTR_delete_index

src/jrd/btr.cpp:904–945

bool BTR_delete_index(thread_db* tdbb, WIN* window, USHORT id)
{
/**************************************
 *
 *	B T R _ d e l e t e _ i n d e x
 *
 **************************************
 *
 * Functional description
 *	Delete an index if it exists.
 *	Return true if index tree was there.
 *
 **************************************/
	SET_TDBB(tdbb);
	const Database* dbb = tdbb->getDatabase();
	CHECK_DBB(dbb);

	// Get index descriptor.  If index doesn't exist, just leave.
	index_root_page* const root = (index_root_page*) window->win_buffer;

	bool tree_exists = false;
	if (id >= root->irt_count)
		CCH_RELEASE(tdbb, window);
	else
	{
		index_root_page::irt_repeat* irt_desc = root->irt_rpt + id;
		CCH_MARK(tdbb, window);
		const PageNumber next(window->win_page.getPageSpaceID(), irt_desc->getRoot());
		tree_exists = (irt_desc->getRoot() != 0);

		// remove the pointer to the top-level index page before we delete it
		irt_desc->setRoot(0);
		irt_desc->irt_flags = 0;
		const PageNumber prior = window->win_page;
		const USHORT relation_id = root->irt_relation;

		CCH_RELEASE(tdbb, window);
		delete_tree(tdbb, relation_id, id, next, prior);
	}

	return tree_exists;
}


bool BTR_description(thread_db* tdbb, jrd_rel* relation, index_root_page* root, index_desc* idx,