4. Understanding Usage Scenarios : How to Run the Benchmark : Create Statistics
 
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Create Statistics
After loading data, we recommend that you run the optimizedb command or CREATE STATISTICS statement to create statistics that the query optimizer uses to create query plans. By default, the optimizedb utility optimizes all tables and columns in the database by looking at all rows.
Note:  We highly recommend creating statistics. Skipping this step may lead to query plans that are inefficient; in extreme cases, it may lead to inability to execute a query.
Note:  Vector will automatically generate statistics for columns in Vector tables that have not already had optimizedb or CREATE STATISTICS run for them. This essentially removes the risk of not creating statistics for some columns, but it does add a slight overhead to the query that triggers the initial creation of the statistics.
To run optimizedb on the database dbtest
Issue the following command from the command line:
optimizedb -zns dbtest
The -zns flag speeds the building of the histogram.