@Override
  public void alterISchema(ISchemaName schemaName, ISchema newSchema)
      throws NoSuchObjectException, MetaException {
    boolean committed = false;
    try {
      openTransaction();
      MISchema oldMSchema = getMISchema(schemaName.getCatName(), schemaName.getDbName(), schemaName.getSchemaName());
      if (oldMSchema == null) {
        throw new NoSuchObjectException("Schema " + schemaName + " does not exist");
      }

      // Don't support changing name or type
      oldMSchema.setCompatibility(newSchema.getCompatibility().getValue());
      oldMSchema.setValidationLevel(newSchema.getValidationLevel().getValue());
      oldMSchema.setCanEvolve(newSchema.isCanEvolve());
      if (newSchema.isSetSchemaGroup()) {
        oldMSchema.setSchemaGroup(newSchema.getSchemaGroup());
      }
      if (newSchema.isSetDescription()) {
        oldMSchema.setDescription(newSchema.getDescription());
      }
      committed = commitTransaction();
    } finally {
      rollbackAndCleanup(committed, null);
    }
  }
Api to fetch all constraints at once
@param request request object
@return all table constraints
@throws MetaException
@throws NoSuchObjectException
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java