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, under normal conditions, “deleted” rows are not truly physically deleted from temporal tables that have a transaction time dimension.
For the same reasons, temporal tables can grow faster than nontemporal tables, depending on how frequently they are modified, and on the nature of those modifications. Tables with transaction-time columns grow monotonically, never shrinking, because rows are never physically deleted from these tables.
The following tables show how temporal tables that have a transaction-time column 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.
- 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.