record

The record type is where a user can define complex data structures by grouping related variables together in the same place. It is similar to struct in C++ or the Series in pandas. It is preferred to use record to hold the grouped data in each row, and a column, in Portex, is a series of records of the same type.

The parameter fields is used in the record to define the member vairables. Each field should have a name and a type. The fields is defined in a one dimentional array manner, so it can easily be expanded into a multi-column row.

name	type	required	description
fields	JSON array	True	It is a one dimentional array. Each element in the array represents a member variable of the record. The member variables are ordered.
fields.<index>	JSON object	True	One element in the array, which represents a member variable of the record.
fields.<index>.name	JSON string	True	The name of the member variable.
fields.<index>.type	JSON string	True	The type of the member variable. It does not have to be a primitive type. It could be any type defined in the context.
fields.<index>.<type-param>	-	False	Type related parameters.

Examples:

1. a 2D point which uses x and y to represent its coordinates:

   ---
   type: record
   fields:
     - name: x
       type: int32
   
     - name: y
       type: int32
   

   In a tabular view:

   x	y
   <x coordinate>	<y coordinate>

2. a student record which contains the basic information of a student:

   ---
   type: record
   fields:
     - name: name
       type: string
   
     - name: gender
       type: enum
       values: [male, female, other]
   
     - name: age
       type: int32
   
     - name: student number
       type: string
   

   In a tabular view:

   name	gender	age	student number
   <student name>	<student gender>	<student age>	<student number>

3. a 2D line which is represented by two 2D point coordinates:

   ---
   type: record
   fields:
     - name: point1
       type: record
       fields:
         - name: x
           type: int32
   
         - name: y
           type: int32
   
     - name: point2
       type: record
       fields:
         - name: x
           type: int32
   
         - name: y
           type: int32
   

   In a tabular view:

   point1		point2
   x	y	x	y
   <x coordinate>	<y coordinate>	<x coordinate>	<y coordinate>

   This example shows the record can be nested, it can be used to support the multi-indexing feature in a columnar store.