![]() That tends toward a columnar-based file format, using compression to fit more records into each storage block. GROUP BY l_orderkey, o_orderdate, o_shippriorityįor storage optimization considerations, think about reducing the I/O workload at every step. ![]() Sum(l_extendedprice * (1 - l_discount)) as revenue,įROM customer, orders, s3_external_schema.LINEITEM_PART_PARQ The following query accesses only one external table you can use it to highlight the additional processing power provided by the Amazon Redshift Spectrum layer: If you want to perform your tests using Amazon Redshift Spectrum, the following two queries are a good start. You must reference the external table in your SELECT statements by prefixing the table name with the schema name, without needing to create and load the table into Amazon Redshift. You can query an external table using the same SELECT syntax that you use with other Amazon Redshift tables. To recap, Amazon Redshift uses Amazon Redshift Spectrum to access external tables stored in Amazon S3. Location 's3:// //lineitem_csv/' Query data You can create an external schema named s3_external_schema as follows:ĬREATE external table s3_external_schema.LINEITEM_PART_PARQ (ĬREATE external table s3_external_schema.LINEITEM_CSV (
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |