Aggregate Awareness

An aggregate table is a summary table that DBAs build to execute queries faster. Aggregate tables are smaller than detail tables and can be aggregated in a number of ways. Most DBAs will strive for a certain compression ratio. For example, with a 10:1 ratio, the aggregate or summary table should be ten times smaller than the detail table, or for every ten detail rows, there is one summary row.

Before you spend your time reading this section, talk to your DBA to determine if your database will automatically take advantage of aggregate tables. Customers using the newly released HANA in-memory appliance also will not need to use aggregate awareness. Newer versions of databases can automatically rewrite a query to leverage an ...

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