Incremental Restore Examples | Teradata DSA - 17.20 - Incremental Restore Examples - BAR - Data Stream Architecture

Teradata® DSA User Guide

Product
BAR
Data Stream Architecture
Release Number
17.20
Release Date
October 2021
Content Type
User Guide
Publication ID
B035-3150-101K
Language
English (United States)

This example describes how incremental restores work when using full, cumulative, and delta IR-enabled backups in a five day backup strategy.

Save Set Type Description
1 full Contains data from all tables
2 delta Contains changed data blocks since last backup
3 full Contains data from all tables
4 delta Contains changed data blocks since last backup
5 cumulative Contains all changes since previous full backup

If you create an IR-enabled restore job in the BAR Operations portlet and select Latest version (Full), the selected backup save sets will be 5 and 3.

If you create an IR-enabled restore job using Specify a version (Full) in the BAR Operations portlet or <backup_version> in the job xml file, you get the following results:
  • If you select Save Set 1, you get save set 1.
  • If you select Save Set 2, you get save sets 1 and 2.
  • If you select Save Set 5, you get save sets 5 and 3.
Next incremental restore normally applies only one save set at a time. To restore multiple save sets, you will need to run the job multiple times. If you create an IR-enabled restore job using Next incremental restore in the BAR Operations portlet or with <next_incremental_restore>=true, you get the following results:
  • A newly created restore job points to the last created full backup (Sve Set 3 above).
  • If a previous restore has occurred: if the last applied (restored) save set is 1, only save set 2 is used.
  • If any of the conditions that force a full restore have occurred (see Changes That Force Full Restore of IR-Enabled Restore Job) and Save Set 1 was the last restored, then both save set 1 and 2 are selected.

Difference Between CBB Restore and IR-Enabled Restore

This table shows the difference between CBB restore and IR-enabled restore for a daily backup and restore to the DR system.

Save Set Day Type CBB Restores These IR-Enabled Restores These
1 Sunday Full

All data for all tables.

1 1
2 Monday Delta

Data that changed today.

2, 1 2
3 Tuesday Delta

Data that changed today.

3, 2, 1 3
4 Wednesday Cumulative

All changes since the full backup.

4, 1 4
5 Thursday Delta

Data that changed today.

5, 4, 1 5
6 Friday Delta

Data that changed today.

6, 5, 4, 1 6
7 Saturday Delta

Data that changed today.

7, 6, 5, 4, 1 7