The following example writes all the data from a native relational database table to external object storage. The data is partitioned (sorted) by the Analytics Database before being written, and the objects containing the data in external object storage are named to reflect their contents.
SELECT NodeId, AmpId, Sequence, ObjectName, ObjectSize, RecordCount FROM WRITE_NOS ( ON ( SELECT * FROM RiverFlowPerm ) PARTITION BY SiteNo ORDER BY SiteNo USING AUTHORIZATION(authorization_object) LOCATION('YOUR-STORAGE-ACCOUNT/RiverFlowPerm_PartitionBy/') STOREDAS('PARQUET') NAMING('DISCRETE') MANIFESTFILE('YOUR-STORAGE-ACCOUNT/RiverFlowPerm_PartitionBy/flowdata_manifest.json') INCLUDE_ORDERING('TRUE') MAXOBJECTSIZE('4MB') COMPRESSION('GZIP') ) AS d ORDER BY AmpId;
Four rows from an example result set are presented here in a vertical layout (column names on the left) for a more efficient presentation:
NodeId 33 AmpId 0 Sequence 1 ObjectName YOUR-STORAGE-ACCOUNT/RiverFlowPerm_PartitionBy/09497500/object_33_0_1.parquet ObjectSize 27682 RecordCount 2944 NodeId 33 AmpId 0 Sequence 1 ObjectName YOUR-STORAGE-ACCOUNT/RiverFlowPerm_PartitionBy/09513780/object_33_0_1.parquet ObjectSize 19136 RecordCount 2941 NodeId 33 AmpId 0 Sequence 1 ObjectName YOUR-STORAGE-ACCOUNT/RiverFlowPerm_PartitionBy/09424900/object_33_0_1.parquet ObjectSize 23174 RecordCount 2946 NodeId 33 AmpId 0 Sequence 1 ObjectName YOUR-STORAGE-ACCOUNT/RiverFlowPerm_PartitionBy/flowdata_manifest.json ObjectSize 513 RecordCount ? [...]
Important things in this example:
- Each row of the result set describes one object written to external object storage that contains data from Vantage.
- Each data object contains data from one partition created according to the PARTITION BY clause. 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, the object names include the values for SiteNo. In the object name,YOUR-STORAGE-ACCOUNT/RiverFlowPerm_PartitionBy/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 object data includes data from the ORDER BY column, the site number from which the data in that row was collected.
- The MANIFESTFILE option causes a manifest file to be written to external object storage. The manifest file lists all objects that WRITE_NOS wrote.