Process for Changing the Map for a Table | VantageCloud Lake - A Simple Process for Changing the Map for a Table

Process for Changing the Map for a Table | VantageCloud Lake - A Simple Process for Changing the Map for a Table - Teradata Vantage

Teradata® VantageCloud Lake

Deployment

VantageCloud

Edition

Lake

Product

Teradata Vantage

Published

January 2023

Language

English (United States)

Last Update

2024-04-03

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phg1621910019905.ditamap

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pny1626732985837.ditaval

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phg1621910019905

The following process is a simple way to change the map a table uses:

Query the view TableToSparseMapSizingV(X). This view recommends a map for each table and shows when to change the current map.
For example, the following request produces a list of tables that Teradata recommends use a sparse map but are now using a contiguous map:
```
SELECT DatabaseName, TableName FROM TDMaps.TableToSparseMapSizingV WHERE RecommendedMap LIKE '%Sparse%' AND CurrentMapKind = 'C';
```
The following request produces a list of tables that Teradata recommends use a different map type (either sparse or contiguous) than their current type:
```
SELECT DatabaseName, TableName FROM TDMaps.TableToSparseMapSizingV WHERE MapOk = 'N';
```
If you decide to have a table use a different map, issue an ALTER TABLE request to name a different map for the table or use the Mover stored procedure, described later. To use ALTER TABLE, you must have the DROP privilege on the table you want to alter. See ALTER TABLE (Map and Colocation Form).