Later, when the CREATE TABLE AS SELECT statement selects data from the external table, the database will use the reject options to determine the number or percentage of rows that can fail to import before it stops the import. Instead, they're specified here so that the database can use them at a later time when it imports data from the external table. REJECT options don't apply at the time this CREATE EXTERNAL TABLE AS SELECT statement is run. To create an external file format, use CREATE EXTERNAL FILE FORMAT (Transact-SQL). Specifies the name of the external file format object that contains the format for the external data file. To create an external data source, use CREATE EXTERNAL DATA SOURCE (Transact-SQL). The location is either a Hadoop cluster or an Azure Blob storage. Specifies the name of the external data source object that contains the location where the external data is stored or will be stored. SQL Server 2022 (16.x) supports Azure Data Lake Storage Gen2, Azure Storage Account V2, and S3-compatible object storage. If the destination is S3-compatible object storage, a bucket must first exist, but PolyBase can create subfolders if necessary. Prefix://path provides the connectivity protocol (prefix), path and optionally the port, to the external data source, where the result of the SELECT statement will be written. LOCATION must point to a folder and have a trailing /, for example: aggregated_data/.Īpplies to: SQL Server 2022 (16.x) and later The external files are written to hdfs_folder and named QueryID_date_time_ID.format, where ID is an incremental identifier and format is the exported data format. PolyBase creates the path and folder if it doesn't already exist. The location is a folder name and can optionally include a path that's relative to the root folder of the Hadoop cluster or Blob storage. Specifies where to write the results of the SELECT statement on the external data source. ) ]Īpplies to: Azure Synapse Analytics and Analytics Platform System For an external table, relational database stores only the table metadata. The one- to three-part name of the table to create in the database. | REJECT_SAMPLE_VALUE = reject_sample_valueĪrguments. Transact-SQL syntax conventions Syntax CREATE EXTERNAL TABLE ĭATA_SOURCE = external_data_source_name , For more information, see CETAS with Synapse SQL. The capabilities and security of CETAS for serverless pools in Azure Synapse Analytics are different from SQL Server.
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