Help Center/ Data Warehouse Service/ SQL Syntax Reference/ SQL Syntax Reference (9.1.1.x)/ Functions and Operators/ EXTERNAL SCHEMA System Functions
Updated on 2026-07-02 GMT+08:00
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EXTERNAL SCHEMA System Functions

System functions related to EXTERNAL SCHEMA are supported only in clusters of version 8.3.0 or later.

pg_get_external_schema_table_list(schema_name text)

Description: Obtains the full table name information of an external schema. Only LakeFormation is supported.

Input parameter: schema_name indicates the name of the external schema.

Return type: SETOF record

Example:

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SELECT * FROM pg_get_external_schema_table_list('ex_lf');
 database_name |           table_name
---------------+---------------------------------
 dws-ci-hlt-db | lf_hms_lineitem_parq
 dws-ci-hlt-db | lf_hms_lineitem_parq
 dws-ci-hlt-db | lf_hms_part_parq
 dws-ci-hlt-db | lf_hms_part_parq
 dws-ci-hlt-db | lf_hms_supplier_parq
 dws-ci-hlt-db | lf_hms_partsupp_parq
 dws-ci-hlt-db | lf_hms_partsupp_parq
 dws-ci-hlt-db | lf_hms_nation_parq
 dws-ci-hlt-db | lf_hms_region_parq
 dws-ci-hlt-db | lf_hms_customer_parq
(10 rows)

pg_get_external_schema_table_options(schema_name text, table_name text)

Description: Obtains the attribute information of an external schema table.

Input parameters: schema_name indicates the name of the external schema, and table_name indicates the table name.

Return type: SETOF record

Example:

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SELECT * FROM pg_get_external_schema_table_options('ex_lf', 'test_lf');
 option_name |            option_value
-------------+------------------------------------
 encoding    | utf8
 format      | parquet
 foldername  | /***/***/***
(3 rows)

pg_get_external_schema_table_col(schema_name text, table_name text)

Description: Obtains the column information of an external schema table.

Input parameters: schema_name indicates the name of the external schema, and table_name indicates the table name.

Return type: SETOF record

Example:

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SELECT * FROM pg_get_external_schema_table_col('ex_lf', 'test_lf');
        col_name        |   col_type    | part_col
------------------------+---------------+----------
 field_smallint         | smallint      | f
 field_int              | int           | f
 field_integer          | int           | f
 field_bigint           | bigint        | f
 field_float            | float         | f
 field_double           | double        | f
 field_double_precision | double        | f
 field_decimal          | decimal(10,0) | f
 field_numeric          | decimal(10,0) | f
 field_timestamp        | timestamp     | f
 field_date             | date          | f
 field_varchar          | varchar(5)    | f
 field_char             | char(5)       | f
 field_boolean          | boolean       | f
 field_string           | string        | f
(15 rows)
Parent Topic: Functions and Operators