SDF Information Schema
Overview
During compilation, SDF creates a comprehensive Information Schema (IF) which contains metadata about your workspace. This metadata includes basic information such as tables, columns, data types, and descriptions along with more complex metadata like column level lineage, and data classifiers.
This workspace IF can be used to enrich data catalogs, and queried to power Checks. Under the hood, SDF stores the analysis output as Parquet.
Information Schema
The below tables represent the SDF Information Schema. They are always accessible, after any compilation, in the sdftarget under sdftarget/dbg/data/system/information_schema::sdf
You may dynamically query the information schema in any valid SDF workspace.
To query your tables:
To query your columns:
To query your column_lineage:
The information schema tables have the following schemas.
Information Schema DDLs
Below are the DDLs representing these tables in SQL.
—information_schemas.sql
CREATE TABLE sdf.information_schema.tables(
“table_id” varchar not null,
“catalog_name” varchar not null,
“schema_name” varchar not null,
“table_name” varchar not null,
“depends_on” array<varchar>,
“depended_on_by” array<varchar>,
“description” varchar,
“dialect” varchar not null,
“materialization” varchar,
“purpose” varchar,
“origin” varchar,
“classifiers” array<varchar>,
“source_locations” array<varchar>,
“meta” map<varchar not null, varchar>
);
CREATE TABLE sdf.information_schema.columns(
“table_id” varchar not null,
“catalog_name” varchar not null,
“schema_name” varchar not null,
“table_name” varchar not null,
“depends_on” array<varchar>,
“depended_on_by” array<varchar>,
“description” varchar,
“dialect” varchar not null,
“materialization” varchar,
“purpose” varchar,
“origin” varchar,
“classifiers” array<varchar>,
“source_locations” array<varchar>,
“meta” map<varchar not null, varchar>
);
CREATE TABLE sdf.information_schema.table_lineage(
“from_table_id” varchar,
“to_table_id” varchar,
“lineage_kind” varchar
);
CREATE TABLE sdf.information_schema.column_lineage(
“from_table_id” varchar,
“from_column_id” varchar,
“to_table_id” varchar,
“to_column_id” varchar,
“lineage_kind” varchar
);