Feature Request: Support TABLESAMPLE

[dpxcc]

The TABLESAMPLE clause is useful for sampling from large tables, but pg_duckdb doesn't support it right now due to syntax differences in TABLESAMPLE clause between Postgres and DuckDB: https://duckdb.org/docs/sql/samples.html

SET duckdb.force_execution = ON;
CREATE TABLE t (a int);
SELECT * FROM t TABLESAMPLE SYSTEM (10);

throws

WARNING:  (PGDuckDB/CreatePlan) Prepared query returned an error: 'Parser Error: Sample method System cannot be used with a discrete sample count, either switch to reservoir sampling or use a sample_size
 a 
---
(0 rows)

but it could be an error if we added some DuckDB-only function to the query

[JelteF]

I guess this should be fairly easy to support by changing get_tablesample_def to include the % sign, which duckdb requires and postgres doesn't want.

pg_duckdb/src/vendor/pg_ruleutils_17.c

Line 12408 in 7e21cbe

get_tablesample_def(TableSampleClause *tablesample, deparse_context *context)