fix: Parquet udfs take in PgRelation

[rebasedming]

Ticket(s) Closed

• Closes s3_endpoint setting is getting lost for parquet_describe #207

What

Instead of taking in the file strings, parquet_schema and parquet_describe take in the foreign table relation, which allows us to load in the user mapping options.

BEFORE:

SELECT * FROM parquet_describe('/path/to/file.parquet');

AFTER:

SELECT * FROM parquet_describe('TABLE_NAME');

Why

Fixes a bug where user mapping options were not getting loaded in to new sessions.

How

Tests

[github-actions]

A schema difference was detected.

A suggested "upgrade.sql" script entry might be:

DROP FUNCTION IF EXISTS parquet_describe(files text);
CREATE OR REPLACE FUNCTION parquet_describe(relation regclass) RETURNS TABLE(column_name text, column_type text, "null" text, key text, "default" text, extra text) AS 'MODULE_PATHNAME', 'parquet_describe_wrapper' LANGUAGE c STRICT;
DROP FUNCTION IF EXISTS parquet_schema(files text);
CREATE OR REPLACE FUNCTION parquet_schema(relation regclass) RETURNS TABLE(file_name text, name text, type text, type_length text, repetition_type text, num_children pg_catalog.int8, converted_type text, scale pg_catalog.int8, "precision" pg_catalog.int8, field_id pg_catalog.int8, logical_type text) AS 'MODULE_PATHNAME', 'parquet_schema_wrapper' LANGUAGE c STRICT;

The full diff between both schemas is:

217c217
< -- src/api/parquet.rs:48
---
> -- src/api/parquet.rs:52
220c220
< 	"files" TEXT /* &str */
---
> 	"relation" regclass /* pgrx::rel::PgRelation */
270c270
< -- src/api/parquet.rs:66
---
> -- src/api/parquet.rs:73
273c273
< 	"files" TEXT /* &str */
---
> 	"relation" regclass /* pgrx::rel::PgRelation */