Location Alignment

In the Hive Metastore, Database definitions, Table Schemas, and Partition details include the location of their datasets. These locations contain a full URI to the dataset. Migrating from one cluster to another requires us to make adjustments to these locations.

The most simple translation will change the namespace of the URI so everything is RELATIVE. This helps reduce the impact of other tools that might be using these datasets outside the Hive Metastore definitions.

Using the RELATIVE 'Location Translation Strategy' is suggested for side-car cluster migrations where you want to keep everything the same as much as possible.

When you are reorganizing, consolidating, or changing storage environments then the ALIGNED 'Location Translation Strategy' will aid in that process. We suggest building out Warehouse Plans for each database for maximum control of that movement.

Attributes of location transformations:

Global Warehouse Directories
Environment Warehouse Directories

Target Namespace

Warehouse Plans

Order of Evaluation

Order of Evaluation means that we will evaluate the attribute in the describe order and once a valid mapping is found, we will stop the evaluation. Evaluation order depends on the translation type as well.

Target Namespace
Warehouse Plans (when defined)
Global Warehouse Directories
Environment Warehouse Directories (under certain conditions)

Target Namespace

Translation Types

Translation types are used to determine how the location should be transformed. The following are the translation types are ALIGNED and RELATIVE.

Legend

Icon	Description
	Valid
	Invalid
	Ignored
	SQL
	Distcp
	Manual
	Automatic
	Optional
	Metastore Direct
	Global Warehouse
	Warehouse Plan

Translation Scenarios

		Required	Notes
DUMP	RELATIVE
	ALIGNED
SCHEMA_ONLY	RELATIVE		Using distcp here when either table or partition locations aren't standard, will result in data loss because we're not inspecting all the locations through the Metastore Direct connection. It's recommended to use `ALIGNED` with `distcp` to build an accurate `distcp` plan.
	ALIGNED	when Warehouse Plan(s) used (Optional)
SQL	RELATIVE
	ALIGNED	(Optional)
EXPORT_IMPORT	RELATIVE
	ALIGNED	(Optional)
HYBRID	RELATIVE
	ALIGNED	(Optional)
STORAGE_MIGRATION	RELATIVE
	ALIGNED	when Warehouse Plan(s) used (Optional)
LINKED	RELATIVE
	ALIGNED
COMMON	RELATIVE
	ALIGNED

Last modified: 14 April 2025