You can specify the COPY command option to load data from Amazon S3 to Amazon Redshift cluster. The COPY command automatically determines the best compression encoding for the column when there is an empty table with no compression encoding specified to load the data to Amazon S3.

When you apply the compression encoding, the first 100,000 rows are read and the best compression encoding for the columns are determined. Then, the compression encoding is applied to the entire table.

You can use the following configuration parameters for managing the automatic compression through COPY command:

Set

COMPUPDATE=ON

to override the compression if you have defined the compression encoding.

Set

COMPROWS

to override the default 100,0000 rows.

The following image shows the

Copy Options

properties:

You can specify the compression encoding manually for the Amazon Redshift columns when you create a target and specify the target schema definition at design time.

You can run the ANALYZE command manually when the Amazon Redshift table is idle. When you run the ANALYZE command, the compression analysis is performed and a report is generated with the specified compression encoding for the tables.