public KVPair writeDirectIndex(LocatedRow locatedRow) throws IOException, StandardException {
    assert locatedRow != null : "locatedRow passed in is null";
    ExecRow execRow = locatedRow.getRow();
    getSerializers(execRow);
    EntryAccumulator keyAccumulator = getKeyAccumulator();
    keyAccumulator.reset();
    boolean hasNullKeyFields = false;
    for (int i = 0; i < execRow.nColumns(); i++) {
      if (execRow.getColumn(i + 1) == null || execRow.getColumn(i + 1).isNull()) {
        hasNullKeyFields = true;
        accumulateNull(keyAccumulator, i, indexFormatIds[i]);
      } else {
        byte[] data = serializers[i].encodeDirect(execRow.getColumn(i + 1), false);
        accumulate(
            keyAccumulator, i, indexFormatIds[i], index.getDescColumns(i), data, 0, data.length);
      }
    }
    // add the row key to the end of the index key
    byte[] srcRowKey = Encoding.encodeBytesUnsorted(locatedRow.getRowLocation().getBytes());

    EntryEncoder rowEncoder = getRowEncoder();
    MultiFieldEncoder entryEncoder = rowEncoder.getEntryEncoder();
    entryEncoder.reset();
    entryEncoder.setRawBytes(srcRowKey);
    byte[] indexValue = rowEncoder.encode();
    byte[] indexRowKey;
    if (index.getUnique()) {
      boolean nonUnique =
          index.getUniqueWithDuplicateNulls() && (hasNullKeyFields || !keyAccumulator.isFinished());
      indexRowKey = getIndexRowKey(srcRowKey, nonUnique);
    } else indexRowKey = getIndexRowKey(srcRowKey, true);
    return new KVPair(indexRowKey, indexValue, KVPair.Type.INSERT);
  }
  /**
   * Get the constraint type out of the row.
   *
   * @param row The row from sysconstraints
   * @return int The constraint type as an int
   * @throws StandardException thrown on failure
   */
  protected int getConstraintType(ExecRow row) throws StandardException {
    DataValueDescriptor col;
    int constraintIType;
    String constraintSType;

    /* 4th column is TYPE (char(1)) */
    col = row.getColumn(SYSCONSTRAINTS_TYPE);
    constraintSType = col.getString();
    assert constraintSType.length() == 1 : "Fourth column type incorrect";

    switch (constraintSType.charAt(0)) {
      case 'P':
        constraintIType = DataDictionary.PRIMARYKEY_CONSTRAINT;
        break;
      case 'U':
        constraintIType = DataDictionary.UNIQUE_CONSTRAINT;
        break;
      case 'C':
        constraintIType = DataDictionary.CHECK_CONSTRAINT;
        break;
      case 'F':
        constraintIType = DataDictionary.FOREIGNKEY_CONSTRAINT;
        break;
      default:
        assert false : "Fourth column value invalid"; // assertion failure
        constraintIType = -1;
    }

    return constraintIType;
  }
  /**
   * Get the table ID of the row.
   *
   * @param row The row from sysconstraints
   * @return UUID The table id
   * @throws StandardException thrown on failure
   */
  protected UUID getTableId(ExecRow row) throws StandardException {
    DataValueDescriptor col;
    String tableUUIDString;

    /* 2nd column is TABLEID (UUID - char(36)) */
    col = row.getColumn(SYSCONSTRAINTS_TABLEID);
    tableUUIDString = col.getString();
    return getUUIDFactory().recreateUUID(tableUUIDString);
  }
  /**
   * Get the schema ID of the row.
   *
   * @param row The row from sysconstraints
   * @return UUID The schema
   * @throws StandardException thrown on failure
   */
  protected UUID getSchemaId(ExecRow row) throws StandardException {
    DataValueDescriptor col;
    String schemaUUIDString;

    /* 5th column is SCHEMAID (UUID - char(36)) */
    col = row.getColumn(SYSCONSTRAINTS_SCHEMAID);
    schemaUUIDString = col.getString();
    return getUUIDFactory().recreateUUID(schemaUUIDString);
  }
  /**
   * Get the constraint name of the row.
   *
   * @param row The row from sysconstraints
   * @return UUID The constraint name
   * @throws StandardException thrown on failure
   */
  protected String getConstraintName(ExecRow row) throws StandardException {
    DataValueDescriptor col;
    String constraintName;

    /* 3rd column is CONSTRAINTNAME (char(128)) */
    col = row.getColumn(SYSCONSTRAINTS_CONSTRAINTNAME);
    constraintName = col.getString();
    return constraintName;
  }
  /**
   * Get the constraint ID of the row.
   *
   * @param row The row from sysconstraints
   * @return UUID The constraint id
   * @throws StandardException thrown on failure
   */
  protected UUID getConstraintId(ExecRow row) throws StandardException {
    DataValueDescriptor col;
    String constraintUUIDString;

    /* 1st column is CONSTRAINTID (UUID - char(36)) */
    col = row.getColumn(SYSCONSTRAINTS_CONSTRAINTID);
    constraintUUIDString = col.getString();
    return getUUIDFactory().recreateUUID(constraintUUIDString);
  }
  /**
   * Make a ConstraintDescriptor out of a SYSCONSTRAINTS row
   *
   * @param row a SYSCONSTRAINTS row
   * @param parentTupleDescriptor Subconstraint descriptor with auxiliary info.
   * @param dd dataDictionary
   * @throws StandardException thrown on failure
   */
  public TupleDescriptor buildDescriptor(
      ExecRow row, TupleDescriptor parentTupleDescriptor, DataDictionary dd)
      throws StandardException {
    ConstraintDescriptor constraintDesc = null;

    if (SanityManager.DEBUG) {
      SanityManager.ASSERT(
          row.nColumns() == SYSCONSTRAINTS_COLUMN_COUNT,
          "Wrong number of columns for a SYSCONSTRAINTS row");
    }

    DataValueDescriptor col;
    ConglomerateDescriptor conglomDesc;
    DataDescriptorGenerator ddg;
    TableDescriptor td = null;
    int constraintIType = -1;
    int[] keyColumns = null;
    UUID constraintUUID;
    UUID schemaUUID;
    UUID tableUUID;
    UUID referencedConstraintId = null;
    SchemaDescriptor schema;
    String tableUUIDString;
    String constraintName;
    String constraintSType;
    String constraintStateStr;
    boolean constraintEnabled;
    int referenceCount;
    String constraintUUIDString;
    String schemaUUIDString;
    SubConstraintDescriptor scd;

    if (SanityManager.DEBUG) {
      if (!(parentTupleDescriptor instanceof SubConstraintDescriptor)) {
        SanityManager.THROWASSERT(
            "parentTupleDescriptor expected to be instanceof "
                + "SubConstraintDescriptor, not "
                + parentTupleDescriptor.getClass().getName());
      }
    }

    scd = (SubConstraintDescriptor) parentTupleDescriptor;

    ddg = dd.getDataDescriptorGenerator();

    /* 1st column is CONSTRAINTID (UUID - char(36)) */
    col = row.getColumn(SYSCONSTRAINTS_CONSTRAINTID);
    constraintUUIDString = col.getString();
    constraintUUID = getUUIDFactory().recreateUUID(constraintUUIDString);

    /* 2nd column is TABLEID (UUID - char(36)) */
    col = row.getColumn(SYSCONSTRAINTS_TABLEID);
    tableUUIDString = col.getString();
    tableUUID = getUUIDFactory().recreateUUID(tableUUIDString);

    /* Get the TableDescriptor.
     * It may be cached in the SCD,
     * otherwise we need to go to the
     * DD.
     */
    if (scd != null) {
      td = scd.getTableDescriptor();
    }
    if (td == null) {
      td = dd.getTableDescriptor(tableUUID);
    }

    /* 3rd column is NAME (varchar(128)) */
    col = row.getColumn(SYSCONSTRAINTS_CONSTRAINTNAME);
    constraintName = col.getString();

    /* 4th column is TYPE (char(1)) */
    col = row.getColumn(SYSCONSTRAINTS_TYPE);
    constraintSType = col.getString();
    if (SanityManager.DEBUG) {
      SanityManager.ASSERT(constraintSType.length() == 1, "Fourth column type incorrect");
    }

    boolean typeSet = false;
    switch (constraintSType.charAt(0)) {
      case 'P':
        constraintIType = DataDictionary.PRIMARYKEY_CONSTRAINT;
        typeSet = true;
        // fall through

      case 'U':
        if (!typeSet) {
          constraintIType = DataDictionary.UNIQUE_CONSTRAINT;
          typeSet = true;
        }
        // fall through

      case 'F':
        if (!typeSet) constraintIType = DataDictionary.FOREIGNKEY_CONSTRAINT;
        if (SanityManager.DEBUG) {
          if (!(parentTupleDescriptor instanceof SubKeyConstraintDescriptor)) {
            SanityManager.THROWASSERT(
                "parentTupleDescriptor expected to be instanceof "
                    + "SubKeyConstraintDescriptor, not "
                    + parentTupleDescriptor.getClass().getName());
          }
        }
        conglomDesc =
            td.getConglomerateDescriptor(
                ((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId());
        /* Take care the rare case of conglomDesc being null.  The
         * reason is that our "td" is out of date.  Another thread
         * which was adding a constraint committed between the moment
         * we got the table descriptor (conglomerate list) and the
         * moment we scanned and got the constraint desc list.  Since
         * that thread just added a new row to SYSCONGLOMERATES,
         * SYSCONSTRAINTS, etc.  We wouldn't have wanted to lock the
         * system tables just to prevent other threads from adding new
         * rows.
         */
        if (conglomDesc == null) {
          // we can't be getting td from cache because if we are
          // here, we must have been in dd's ddl mode (that's why
          // the ddl thread went through), we are not done yet, the
          // dd ref count is not 0, hence it couldn't have turned
          // into COMPILE_ONLY mode
          td = dd.getTableDescriptor(tableUUID);
          if (scd != null) scd.setTableDescriptor(td);
          // try again now
          conglomDesc =
              td.getConglomerateDescriptor(
                  ((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId());
        }

        if (SanityManager.DEBUG) {
          SanityManager.ASSERT(
              conglomDesc != null, "conglomDesc is expected to be non-null for backing index");
        }
        referencedConstraintId =
            ((SubKeyConstraintDescriptor) parentTupleDescriptor).getKeyConstraintId();
        keyColumns = conglomDesc.getIndexDescriptor().baseColumnPositions();
        break;

      case 'C':
        constraintIType = DataDictionary.CHECK_CONSTRAINT;
        if (SanityManager.DEBUG) {
          if (!(parentTupleDescriptor instanceof SubCheckConstraintDescriptor)) {
            SanityManager.THROWASSERT(
                "parentTupleDescriptor expected to be instanceof "
                    + "SubCheckConstraintDescriptor, not "
                    + parentTupleDescriptor.getClass().getName());
          }
        }
        break;

      default:
        if (SanityManager.DEBUG) {
          SanityManager.THROWASSERT("Fourth column value invalid");
        }
    }

    /* 5th column is SCHEMAID (UUID - char(36)) */
    col = row.getColumn(SYSCONSTRAINTS_SCHEMAID);
    schemaUUIDString = col.getString();
    schemaUUID = getUUIDFactory().recreateUUID(schemaUUIDString);

    schema = dd.getSchemaDescriptor(schemaUUID, null);

    /* 6th column is STATE (char(1)) */
    col = row.getColumn(SYSCONSTRAINTS_STATE);
    constraintStateStr = col.getString();
    if (SanityManager.DEBUG) {
      SanityManager.ASSERT(constraintStateStr.length() == 1, "Sixth column (state) type incorrect");
    }

    switch (constraintStateStr.charAt(0)) {
      case 'E':
        constraintEnabled = true;
        break;
      case 'D':
        constraintEnabled = false;
        break;
      default:
        constraintEnabled = true;
        if (SanityManager.DEBUG) {
          SanityManager.THROWASSERT(
              "Invalidate state value '" + constraintStateStr + "' for constraint");
        }
    }

    /* 7th column is REFERENCECOUNT, boolean */
    col = row.getColumn(SYSCONSTRAINTS_REFERENCECOUNT);
    referenceCount = col.getInt();

    /* now build and return the descriptor */

    switch (constraintIType) {
      case DataDictionary.PRIMARYKEY_CONSTRAINT:
        constraintDesc =
            ddg.newPrimaryKeyConstraintDescriptor(
                td,
                constraintName,
                false, // deferable,
                false, // initiallyDeferred,
                keyColumns, // genReferencedColumns(dd, td), //int referencedColumns[],
                constraintUUID,
                ((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId(),
                schema,
                constraintEnabled,
                referenceCount);
        break;

      case DataDictionary.UNIQUE_CONSTRAINT:
        constraintDesc =
            ddg.newUniqueConstraintDescriptor(
                td,
                constraintName,
                false, // deferable,
                false, // initiallyDeferred,
                keyColumns, // genReferencedColumns(dd, td), //int referencedColumns[],
                constraintUUID,
                ((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId(),
                schema,
                constraintEnabled,
                referenceCount);
        break;

      case DataDictionary.FOREIGNKEY_CONSTRAINT:
        if (SanityManager.DEBUG) {
          SanityManager.ASSERT(
              referenceCount == 0, "REFERENCECOUNT column is nonzero for fk constraint");
        }

        constraintDesc =
            ddg.newForeignKeyConstraintDescriptor(
                td,
                constraintName,
                false, // deferable,
                false, // initiallyDeferred,
                keyColumns, // genReferencedColumns(dd, td), //int referencedColumns[],
                constraintUUID,
                ((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId(),
                schema,
                referencedConstraintId,
                constraintEnabled,
                ((SubKeyConstraintDescriptor) parentTupleDescriptor).getRaDeleteRule(),
                ((SubKeyConstraintDescriptor) parentTupleDescriptor).getRaUpdateRule());
        break;

      case DataDictionary.CHECK_CONSTRAINT:
        if (SanityManager.DEBUG) {
          SanityManager.ASSERT(
              referenceCount == 0, "REFERENCECOUNT column is nonzero for check constraint");
        }

        constraintDesc =
            ddg.newCheckConstraintDescriptor(
                td,
                constraintName,
                false, // deferable,
                false, // initiallyDeferred,
                constraintUUID,
                ((SubCheckConstraintDescriptor) parentTupleDescriptor).getConstraintText(),
                ((SubCheckConstraintDescriptor) parentTupleDescriptor)
                    .getReferencedColumnsDescriptor(),
                schema,
                constraintEnabled);
        break;
    }
    return constraintDesc;
  }