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Optiq JSON model reference

Elements

Root

{
  version: '1.0',
  defaultSchema: 'mongo',
  schemas: [ Schema... ]
}

version (required string) must have value 1.0.

defaultSchema (optional string). If specified, it is the name (case-sensitive) of a schema defined in this model, and will become the default schema for connections to Optiq that use this model.

schemas (optional list of Schema elements).

Schema

Occurs within root.schemas.

{
  name: 'foodmart',
  path: ['lib'],
  cache: true,
  materializations: [ Materialization... ]
}

name (required string) is the name of the schema.

type (optional string, default map) indicates sub-type. Values are:

path (optional list) is the SQL path that is used to resolve functions used in this schema. If specified it must be a list, and each element of the list must be either a string or a list of strings. For example,

  path: [ ['usr', 'lib'], 'lib' ]

declares a path with two elements: the schema '/usr/lib' and the schema '/lib'. Most schemas are at the top level, so you can use a string.

materializations (optional list of Materialization) defines the tables in this schema that are materializations of queries.

cache (optional boolean, default true) tells Optiq whether to cache metadata (tables, functions and sub-schemas) generated by this schema.

  • If false, Optiq will go back to the schema each time it needs metadata, for example, each time it needs a list of tables in order to validate a query against the schema.

  • If true, Optiq will cache the metadata the first time it reads it. This can lead to better performance, especially if name-matching is case-insensitive.

However, it also leads to the problem of cache staleness. A particular schema implementation can override the Schema.contentsHaveChangedSince method to tell Optiq when it should consider its cache to be out of date.

Tables, functions and sub-schemas explicitly created in a schema are not affected by this caching mechanism. They always appear in the schema immediately, and are never flushed.

Map Schema

Like base class Schema, occurs within root.schemas.

{
  name: 'foodmart',
  type: 'map',
  tables: [ Table... ],
  functions: [ Function... ]
}

name, type, path, cache, materializations inherited from Schema.

tables (optional list of Table elements) defines the tables in this schema.

functions (optional list of Function elements) defines the functions in this schema.

Custom Schema

Like base class Schema, occurs within root.schemas.

{
  name: 'mongo',
  type: 'custom',
  factory: 'net.hydromatic.optiq.impl.mongodb.MongoSchemaFactory',
  operand: {
    host: 'localhost',
    database: 'test'
  }
}

name, type, path, cache, materializations inherited from Schema.

factory (required string) is the name of the factory class for this schema. Must implement interface net.hydromatic.optiq.SchemaFactory and have a public default constructor.

operand (optional map) contains attributes to be passed to the factory.

JDBC Schema

Like base class Schema, occurs within root.schemas.

{
  name: 'foodmart',
  type: 'jdbc',
  jdbcDriver: TODO,
  jdbcUrl: TODO,
  jdbcUser: TODO,
  jdbcPassword: TODO,
  jdbcCatalog: TODO,
  jdbcSchema: TODO
}

name, type, path, cache, materializations inherited from Schema.

jdbcDriver (optional string) is TODO.

jdbcUrl (optional string) is TODO.

jdbcUser (optional string) is TODO.

jdbcPassword (optional string) is TODO.

jdbcCatalog (optional string) is TODO.

jdbcSchema (optional string) is TODO.

Materialization

Occurs within root.schemas.materializations.

TODO

view (optional string) TODO

table (optional string) TODO

sql (optional string) TODO

Table

Occurs within root.schemas.tables.

{
  name: 'sales_fact',
  columns: [ Column... ]
}

name (required string) is the name of this table. Must be unique within the schema.

type (optional string, default custom) indicates sub-type. Values are:

columns (optional list of Column elements)

View

Like base class Table, occurs within root.schemas.tables.

{
  name: 'female_emps',
  type: 'view',
  sql: "select * from emps where gender = 'F'"
}

name, type, columns inherited from Table.

sql (required string) is the SQL definition of the view.

path (optional list) is the SQL path to resolve the query. If not specified, defaults to the current schema.

Custom Table

Like base class Table, occurs within root.schemas.tables.

{
  name: 'female_emps',
  type: 'custom',
  factory: 'TODO',
  operand: {
    todo: 'TODO'
  }
}

name, type, columns inherited from Table.

factory (required string) is the name of the factory class for this table. Must implement interface net.hydromatic.optiq.TableFactory and have a public default constructor.

operand (optional map) contains attributes to be passed to the factory.

Column

Occurs within root.schemas.tables.columns.

TODO

name (required string) is the name of this column.

Function

Occurs within root.schemas.functions.

TODO

name (required string) is the name of this function.

className (required string) is the name of the class that implements this function.

path (optional list of string) is the path for resolving this function.