add test for different config

datafusion/sqllogictest/test_files/information_schema.slt

@@ -259,6 +259,7 @@ datafusion.optimizer.repartition_windows true
 datafusion.optimizer.skip_failed_rules false
 datafusion.optimizer.top_down_join_key_reordering true
 datafusion.sql_parser.collect_spans false
+datafusion.sql_parser.default_null_ordering asc_reverse
 datafusion.sql_parser.dialect generic
 datafusion.sql_parser.enable_ident_normalization true
 datafusion.sql_parser.enable_options_value_normalization false
@@ -356,6 +357,7 @@ datafusion.optimizer.repartition_windows true Should DataFusion repartition data
 datafusion.optimizer.skip_failed_rules false When set to true, the logical plan optimizer will produce warning messages if any optimization rules produce errors and then proceed to the next rule. When set to false, any rules that produce errors will cause the query to fail
 datafusion.optimizer.top_down_join_key_reordering true When set to true, the physical plan optimizer will run a top down process to reorder the join keys
 datafusion.sql_parser.collect_spans false When set to true, the source locations relative to the original SQL query (i.e. [`Span`](sqlparser::tokenizer::Span)) will be collected and recorded in the logical plan nodes.
+datafusion.sql_parser.default_null_ordering asc_reverse Specifies the default null ordering for query results By default, `asc_reverse` is used to follow Postgres's behavior. postgres rule: https://www.postgresql.org/docs/current/queries-order.html
 datafusion.sql_parser.dialect generic Configure the SQL dialect used by DataFusion's parser; supported values include: Generic, MySQL, PostgreSQL, Hive, SQLite, Snowflake, Redshift, MsSQL, ClickHouse, BigQuery, Ansi, DuckDB and Databricks.
 datafusion.sql_parser.enable_ident_normalization true When set to true, SQL parser will normalize ident (convert ident to lowercase when not quoted)
 datafusion.sql_parser.enable_options_value_normalization false When set to true, SQL parser will normalize options value (convert value to lowercase). Note that this option is ignored and will be removed in the future. All case-insensitive values are normalized automatically.

datafusion/sqllogictest/test_files/order.slt

@@ -94,6 +94,74 @@ NULL three
 1 one
 2 two
 
+statement ok
+set datafusion.sql_parser.default_null_ordering = 'desc_reverse';
+
+# test asc with `desc_reverse` null ordering
+
+query IT
+SELECT * FROM (VALUES (1, 'one'), (2, 'two'), (null, 'three')) AS t (num,letter) ORDER BY num
+----
+NULL three
+1 one
+2 two
+
+# test desc with `desc_reverse` null ordering
+
+query IT
+SELECT * FROM (VALUES (1, 'one'), (2, 'two'), (null, 'three')) AS t (num,letter) ORDER BY num DESC
+----
+2 two
+1 one
+NULL three
+
+statement ok
+set datafusion.sql_parser.default_null_ordering = 'nulls_first';
+
+# test asc with `nulls_first` null ordering
+
+query IT
+SELECT * FROM (VALUES (1, 'one'), (2, 'two'), (null, 'three')) AS t (num,letter) ORDER BY num
+----
+NULL three
+1 one
+2 two
+
+# test desc with `nulls_first` null ordering
+
+query IT
+SELECT * FROM (VALUES (1, 'one'), (2, 'two'), (null, 'three')) AS t (num,letter) ORDER BY num DESC
+----
+NULL three
+2 two
+1 one
+
+
+statement ok
+set datafusion.sql_parser.default_null_ordering = 'nulls_last';
+
+# test asc with `nulls_last` null ordering
+
+query IT
+SELECT * FROM (VALUES (1, 'one'), (2, 'two'), (null, 'three')) AS t (num,letter) ORDER BY num
+----
+1 one
+2 two
+NULL three
+
+# test desc with `nulls_last` null ordering
+
+query IT
+SELECT * FROM (VALUES (1, 'one'), (2, 'two'), (null, 'three')) AS t (num,letter) ORDER BY num DESC
+----
+2 two
+1 one
+NULL three
+
+# reset to default null ordering
+statement ok
+set datafusion.sql_parser.default_null_ordering = 'asc_reverse';
+
 # sort
 
 statement ok