2.2.2 Single-chunk tables and multi-chunk tables

(1) What is a single-chunk table?

A single-chunk table is a base table in which only one chunk can be created. The background-import facility cannot be used with single-chunk tables.

For details about chunks and the background-import facility, see 2.14 Background-import facility.

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(2) What is a multi-chunk table?

A multi-chunk table is a base table in which multiple chunks can be created. The background-import facility can be used with multi-chunk tables.

Multi-chunk tables can be categorized into two types: regular multi-chunk tables and archivable multi-chunk tables.

• Regular multi-chunk table

  For regular multi-chunk tables, the background-import facility, which is a basic function for multi-chunk tables, can be used, but the chunk archiving function cannot be used.

• Archivable multi-chunk table

  For archivable multi-chunk tables, both the background-import facility and chunk archiving function can be used.

For details about the chunk archiving function, see 2.15 Chunk archiving function (compressing data in a chunk).

Important

The available functions differ between single and multi-chunk tables. The following table shows the relationship between the table type and the available functions:

Table 2‒1: Relationship between the base table types and functions that can be used

Base table type		Function that can be used
		Background-import facility	Chunk archiving function
Single-chunk table		N	N
Multi-chunk table	Regular multi-chunk table	Y	N
	Archivable multi-chunk table	Y	Y

Legend:

Y: Can be used.

N: Cannot be used.

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(3) Relationship between row store tables and column store tables

When designing a table, the first step is to decide whether to define it as a row store table or column store table. You then decide whether to define it as a single-chunk table or multi-chunk table (regular multi-chunk table or archivable multi-chunk table). Note that you cannot define a column store table as an archivable multi-chunk table.

The following table shows the relationship between row and column store tables and single and multi-chunk tables.

Table 2‒2: Relationship between row and column store tables and single and multi-chunk tables

Base table type	Base table type
	Single-chunk table	Multi-chunk table
		Regular multi-chunk table	Archivable multi-chunk table
Row store table	Y	Y	Y
Column store table	Y	Y	N

Legend:

Y: You can define a table of this type.

N: You cannot define a table of this type.

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