Capacity Planning for Temporal Tables - Teradata Database

Temporal tables typically contain more rows than otherwise equivalent nontemporal tables. This is due to the way rows are automatically added to temporal tables as a result of most kinds of modifications. Furthermore, rows are never physically deleted from system-time or bitemporal tables, but persist in the tables indefinitely.

For these reasons, temporal tables grow faster than nontemporal tables, at a rate that depends on how frequently they are modified, and on the nature of those modifications.

The following tables show how temporal tables that have a system-time dimension can grow depending on the nature and frequency of table modifications. Valid-time tables are likely to experience less growth, because rows in valid-time tables can be physically deleted from the tables.

Use these examples to estimate annual growth of temporal tables for capacity planning.

Table and Row Size Calculation forms are available in Database Design for nontemporal tables.

Note:  

Sequenced modifications are typically historical in nature.

To reflect conservative estimates, the table size increase calculation is based on the maximum number of rows that can be produced by each type of modification.

	System-time Table	Bitemporal Table
Table Size Before Modifications (rows)	100	100
Modification Type	Current (open rows)	FOR PORTION OF
Modifications per Year (percent of rows)	10% (0.19% weekly)	10% (0.19% weekly)
Number of Additional Rows Produced per Modification	1	1, 2, or 3
Largest Table Size After Modifications (rows)	110	130
Annual Increase in Table Size	10%	30%

	System-time Table	Bitemporal Table
Table Size Before Modifications (rows)	100	100
Modification Type	Current	FOR PORTION OF
Modifications per Year (percent of rows)	30% (0.58% weekly)	30% (0.58% weekly)
Number of Additional Rows Produced per Modification	1	1, 2, or 3
Largest Table Size After Modifications (rows)	130	190
Annual Increase in Table Size	30%	90%

	System-time Table	Bitemporal Table
Table Size Before Modifications (rows)	100	100
Modification Type	Current	FOR PORTION OF
Modifications per Year (percent of rows)	50% (0.96% weekly)	50% (0.96% weekly)
Number of Additional Rows Produced per Modification	1	1, 2, or 3
Largest Table Size After Modifications (rows)	150	250
Annual Increase in Table Size	50%	150%