CREATE EXTERNAL TABLE (X100 Only)
Valid in: SQL, ESQL, OpenAPI, ODBC, JDBC, .NET
The CREATE EXTERNAL TABLE statement maps the structure of a data file created outside of Actian X to the structure of an X100 table. The data can then be queried from its original locations.
This statement has the following format:
CREATE EXTERNAL TABLE [IF NOT EXISTS] [schema.]tablename
(column_name data_type {,column_name data_type})
USING provider_name
WITH REFERENCE='reference'
[,FORMAT='format']
[EXTERNAL_ROLE='external_role']
[,OPTIONS=('key'=value {,'key'='value'})]
IF NOT EXISTS
Creates the table if it does not exist and returns without error if the table already exists.
Note: Use this option with caution. The table definition of a preexisting table may differ from that of the CREATE EXTERNAL TABLE IF NOT EXISTS statement.
tablename
Defines the name of the external table to be created.
column_name data_type
Specifies the column name and data type of each column. Each column specification must be separated with a comma.
USING provider_name
Specifies the name of the provider. The only valid provider is SPARK.
Provider Name Application
SPARK Spark
WITH REFERENCE='reference'
(Required) Specifies the reference to the external datasource. This corresponds to the parameter passed to the load method of DataFrameReader or save method of DataFrameWriter. For example:
For database systems: The table name
FORMAT='format'
(Optional) Is a WITH clause option that specifies the format of the external data.
Example formats include: csv, avro, parquet, hive, orc, json, jdbc. For other datasources, format corresponds to the class name that defines that external datasource. For example, for Redshift it would be com.databricks.spark.redshift. This corresponds to the parameter passed to the format method of DataFrameReader/Writer.
When FORMAT is not specified, the Spark-Vector Provider tries to recognize the format for files by looking at the file extension.
EXTERNAL_ROLE='external_role'
Note: This option is not implemented.
OPTIONS
(Optional) Is a WITH clause option that specifies user defined options for the datasource read from or written to. The options are not Actian X-specific; they are given by Spark and correspond to the options method of the DataFrameReader/Writer. For example, for CSV files you can pass any options supported by spark-csv. For additional options supported by various external datasources, see the DataFrameReader documentation at
https://spark.apache.org/docs/latest/api/java/org/apache/spark/sql/DataFrameReader.html.
Useful options are:
'HEADER'='TRUE' | 'FALSE'
Indicates whether the data file contains a header row.
'DELIMITER'='character'
Indicates the character used in the data file as the record delimiter. Example: 'delimiter'='|'
'SCHEMA'='schema'
Specifies the table column definitions, which are required if the data file being loaded does not contain a header row.
Last modified date: 11/09/2022