The following examples write all the data stored in a database table to external object storage. The data is partitioned (sorted) by Advanced SQL Engine before being written. The objects containing the data in external storage are named to reflect the sorted data they contain.
- If not already done, set up or obtain access to the external object storage where you want to write data. Follow the instructions from your external storage vendor.
- Write all the rows from a database table to external object storage:
SELECT * FROM WRITE_NOS ( ON ( SELECT * FROM RiverFlowPerm ) PARTITION BY site_no ORDER BY site_no USING LOCATION('YOUR-OBJECT-STORE-URI/RiverFlowPerm_Discrete/') AUTHORIZATION(MyAuthObj) STOREDAS('PARQUET') COMPRESSION('SNAPPY') NAMING('DISCRETE') INCLUDE_ORDERING('TRUE') ) AS d;
Replace LOCATION with the URI to the external object storage where you want to write the data.Things to note in this example:
- Each row of the result set describes one object written to external storage that contains data from Vantage.
- Each object contains data from one partition created according to the PARTITION BY clause. In this case there is one partition for each data collection site, that is, for each SiteNo column value.
- NAMING('DISCRETE') causes the object names to include the partition name, in this case the object names include the values for SiteNo. In the object name, /S3/s3.amazonaws.com/ie-writenos-bucket/RiverFlowPerm_Discrete/09497500/object_33_0_1.parquet, "09497500" is the SiteNo of the data contained by this object.
- Because the query included INCLUDE_ORDERING('TRUE'), the objects include data from the ORDER BY column(s), in this case the object data includes the site number from which the data in that row was collected.
Your result will be similar to the following:
NodeId 33 AmpId 0 Sequence 1 ObjectName /S3/s3.amazonaws.com/ie-writenos-bucket/RiverFlowPerm_Discrete/09497500/object_33_0_1.parquet ObjectSize 27682 RecordCount 2944 NodeId 33 AmpId 0 Sequence 1 ObjectName /S3/s3.amazonaws.com/ie-writenos-bucket/RiverFlowPerm_Discrete/09513780/object_33_0_1.parquet ObjectSize 19136 RecordCount 2941 NodeId 33 AmpId 0 Sequence 1 ObjectName /S3/s3.amazonaws.com/ie-writenos-bucket/RiverFlowPerm_Discrete/09424900/object_33_0_1.parquet ObjectSize 23174 RecordCount 2946 [...]
The output is displayed vertically for readability.
Example: Write All Rows to External Object Storage, Use PARTITION BY and NAMING('DISCRETE')