org.apache.calcite.schema

Interface SchemaFactory

All Known Implementing Classes:

AbstractSchema.Factory, CloneSchema.Factory, JdbcSchema.Factory, ReflectiveSchema.Factory

public interface SchemaFactory

Factory for Schema objects.

A schema factory allows you to include a custom schema in a model file. For example, here is a model that contains a custom schema whose tables read CSV files. (See the example CSV adapter for more details about this particular adapter.)

{
   "version": "1.0",
   "defaultSchema": "SALES",
   "schemas": [
     {
       "name": "SALES",
       "type": "custom",
       "factory": "org.apache.calcite.adapter.csv.CsvSchemaFactory",
       "mutable": true,
       "operand": {
         directory: "target/test-classes/sales"
       },
       "tables": [
         {
           "name": "FEMALE_EMPS",
           "type": "view",
           "sql": "SELECT * FROM emps WHERE gender = 'F'"
          }
       ]
     }
   ]
 }

If you do not wish to allow model authors to add additional tables (including views) to an instance of your schema, specify 'mutable: false'.

A class that implements SchemaFactory specified in a schema must have a public default constructor.

Method Summary

Modifier and Type	Method and Description
Schema	create(SchemaPlus parentSchema, String name, Map<String,Object> operand) Creates a Schema.

Method Detail

create

Schema create(SchemaPlus parentSchema,
              String name,
              Map<String,Object> operand)

Creates a Schema.

Parameters:

parentSchema - Parent schema

name - Name of this schema

operand - The "operand" JSON property

Returns:

Created schema