DO {{dollar_delimiter}}
DECLARE
  m_cnt bigint;
  m_next bigint;
BEGIN
  IF EXISTS (
    SELECT 1 FROM pg_class c
    INNER JOIN pg_namespace n ON n.oid = c.relnamespace
    WHERE c.relname = {{quote .SequenceName}}
      AND n.nspname = {{quote .SchemaName}}
      AND c.relkind = 'S'
  ) THEN
    SELECT COALESCE(MAX({{quote_ident .ColumnName}}), 0) + 1
    FROM {{qual_table .SchemaName .TableName}}
    INTO m_cnt;

    SELECT CASE WHEN is_called THEN last_value + 1 ELSE last_value END
    FROM {{qual_table .SchemaName .SequenceName}}
    INTO m_next;

    -- Only move the sequence forward; never rewind one that is already past the data.
    IF m_cnt > m_next THEN
      PERFORM setval({{quote (qual_table .SchemaName .SequenceName)}}::regclass, m_cnt, false);
    END IF;
  END IF;
END;
{{dollar_delimiter}};