Sap Hana - Table

Table data structure in the context of SAP HANA.

The dual table is called the dummy table.

select 1 from dummy;

It is possible to change an existing table from one storage type to the other (ALTER TABLE ALTER TYPE).

• only insert (no update)
• select as of …

Column store

• Calculations are typically executed on individual or a small number of columns.
• The table is searched based on the values of a few columns.
• The table has a large number of columns.
• The table has a large number of rows and columnar operations are required (aggregate, scan, and so on)
• High compression rates can be achieved because the majority of the columns contain only a few distinct values (compared to the number of rows).

Row store

• The application needs to process only one single record at one time (many selects and /or updates of single records).
• The application typically needs to access the complete record.
• The columns contain mainly distinct values so compression rate would be low.
• Neither aggregations nor fast searching are required.
• The table has a small number of rows (for example, configuration tables).

SAP Hana - Virtual Table

• LOAD <table_name>
• UNLOAD <table_name>

• Tables
• M_TABLES - Information on row and column tables

TRUNCATE

rename table oldTableName to  newTableName

RENAME TABLE

CREATE Table

See the specific structure:

• Sap Hana - Table Column - Column Store
• Sap Hana - Row tables

• Alter table
• Hana One Alter Table
• Managing Table