@Override
  public ISchema get_ischema(ISchemaName schemaName) throws TException {
    startFunction("get_ischema", ": " + schemaName);
    Exception ex = null;
    ISchema schema = null;
    try {
      schema = getMS().getISchema(schemaName);
      if (schema == null) {
        throw new NoSuchObjectException("No schema named " + schemaName + " exists");
      }
      firePreEvent(new PreReadISchemaEvent(this, schema));
      return schema;
    } catch (MetaException e) {
      LOG.error("Caught exception getting schema", e);
      ex = e;
      throw e;
    } finally {
      endFunction("get_ischema", schema != null, ex);
    }
  }
Api to fetch all table constraints at once.
@param request it consist of catalog name, database name and table name to identify the table in metastore
@return all constraints attached to given table
@throws TException
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HMSHandler.java