presto-main/src/main/java/io/prestosql/connector/system/SystemSplitManager.java/SystemSplitManager/getSplits
class SystemSplitManager:    @Override
    public ConnectorSplitSource getSplits(
            ConnectorTransactionHandle transaction,
            ConnectorSession session,
            ConnectorTableHandle tableHandle,
            SplitSchedulingStrategy splitSchedulingStrategy)
    {
        SystemTableHandle table = (SystemTableHandle) tableHandle;
        TupleDomain<ColumnHandle> constraint = table.getConstraint();

        SystemTable systemTable = tables.getSystemTable(session, table.getSchemaTableName())
                // table might disappear in the meantime
                .orElseThrow(() -> new TableNotFoundException(table.getSchemaTableName()));

        Distribution tableDistributionMode = systemTable.getDistribution();
        if (tableDistributionMode == SINGLE_COORDINATOR) {
            HostAddress address = nodeManager.getCurrentNode().getHostAndPort();
            ConnectorSplit split = new SystemSplit(address, constraint);
            return new FixedSplitSource(ImmutableList.of(split));
        }

        ImmutableList.Builder<ConnectorSplit> splits = ImmutableList.builder();
        ImmutableSet.Builder<InternalNode> nodes = ImmutableSet.builder();
        if (tableDistributionMode == ALL_COORDINATORS) {
            nodes.addAll(nodeManager.getCoordinators());
        }
        else if (tableDistributionMode == ALL_NODES) {
            nodes.addAll(nodeManager.getNodes(ACTIVE));
        }
        Set<InternalNode> nodeSet = nodes.build();
        for (InternalNode node : nodeSet) {
            splits.add(new SystemSplit(node.getHostAndPort(), constraint));
        }
        return new FixedSplitSource(splits.build());
    }