Some services support custom parameters that the driver can leverage to process more efficient queries when filtering results. You can specify custom parameters using the #queryParameter in the column definition.

In addition, the driver supports filtering by parameters of custom languages, such as Jira Query Language (JQL) or Salesforce Object Query Language (SOQL). When the service supports the language specified by the #queryParameter property, the driver passes the query to the service to filter the results based on the parameter value specified by the #default property or by the Where clause in a SQL statement. The service then processes the results before returning them to the driver, thereby reducing the number of web service calls and driver overhead. 

"<table_name>": {
          "#path": ["<host_name>/<endpoint_path>"]
          "<column_name1>":"<data_type1>",
          "<column_name2>":{
               "#type":"<data_type2>",
               "#queryParameter":"<param_name>",
               "#default":"<default_param>"
          }
     },
table_name
is the name of the relational table to which the driver maps the endpoint. For example, people.
host_name
(optional) is the protocol and host name components of the URL endpoint. For example, http://example.com. You can omit this value by specifying the host name using the ServerName property.
endpoint_path
is the path component of the URL endpoint. For example, times. This can be an unparameterized or parameterized path, a path that uses query parameters, or an array of paths. See "Query paths" for examples and more information.
column_name
is the name of the column name that contains the nested object.
data_type
specifies the data type mapping for the column.
param_name
specifies the name of the query parameter that would appear in the request. This can be used for sending the value as a custom language. For example, JQL or SOQL.
default_param
(optional) specifies the argument parameter component of the parameter=value pair used for filtering the request. If the #default property is omitted, the value must be specified in the Where clause when issuing a query.

For example, the following demonstrates an entry for a GET request that defines custom parameters.

"issues": {
          "#path": ["http://example.org/issues"]
          "id":"VarChar",
          "query":{
               "#type":"VarChar",
               "#queryParameter":"jql",
               "#default":"FILTER ON NAME"
          }
     },