That are created and modified with insert, delete, and upsert write operations.įor example, bootstrap tables are not supported. A Hudi Copy On Write table is a collection of Apache Parquet files stored in To query data in Apache Hudi Copy On Write (CoW) format, you can use Amazon Redshift Spectrum external Creating external tables for data managed in To the corresponding columns in the ORC file by column name. The column named nested_col in theĮxternal table is a struct column with subcolumns named The table columns int_col,įloat_col, and nested_col map by column name to columns You can map the same external table to both file structures shown in the previousĮxamples by using column name mapping. When you query a table with the preceding position mapping, the SELECT commandįails on type validation because the structures are different. When you create an external table that references data in an ORC file, you map eachĬolumn in the external table to a column in the ORC data. For more information about querying nested data, see Querying Nested Data with Amazon Redshift Optimized row columnar (ORC) format is a columnar storage file format that supports You use Amazon Redshift Spectrum external tables to query data from files in ORC format. Order by 3 desc salesmonth | eventname | sumĢ008-02 | Die Walkure | 534.00 Mapping external table columns to ORC Group by event.eventname, spectrum.sales_event.salesmonth Where spectrum.sales_event.eventid = event.eventid Select spectrum.sales_event.salesmonth, event.eventname, sum(spectrum.sales_event.pricepaid) Run the following query to select data from the partitioned table. Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-03/event=103/' Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-03/event=102/' Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-03/event=101/' Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-02/event=103/' Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-02/event=102/'
Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-02/event=101/' Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-01/event=103/' Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-01/event=102/' Location 's3://redshift-downloads/tickit/spectrum/salesevent/salesmonth=2008-01/event=101/' The following example adds partitions for The location of the partition folder in Amazon S3. PARTITION, add each partition, specifying the partition column and key value, and The data type canīe SMALLINT, INTEGER, BIGINT, DECIMAL, REAL, DOUBLE PRECISION, BOOLEAN, CHAR, VARCHAR, DATE, or TIMESTAMP data type. The partition key can't be the name of a table column. , _, or #) or end with a tilde (~).Ĭreate an external table and specify the partition key in the PARTITIONED BY Redshift Spectrum ignores hidden files and files that begin with a Redshift Spectrum scans the files in the partition folder and any For example, if you partition by date, you might haveĪnd so on. Store your data in folders in Amazon S3 according to your partition key.Ĭreate one folder for each partition value and name the folder with the Include the $path, $size, and $spectrum_oidĬolumn names in your query, as the following example shows. A SELECT * clause doesn't return the pseudocolumns. $size, and $spectrum_oid column names with double quotation For an example, see Example: Performing correlated subqueries in Redshift Spectrum.
Perform correlated queries with Redshift Spectrum. The $spectrum_oid column provides the ability to Select the $pathĬolumn to view the path to the data files onĪnd select the $size column to view the size of the data files for each row Pseudocolumnsīy default, Amazon Redshift creates external tables with the pseudocolumns $path, To view external tables, query the SVV_EXTERNAL_TABLES system view. Location 's3://redshift-downloads/tickit/spectrum/sales/'
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