Change SQL dialect to PostgreSQL

[alamb]

Note: migrated from original JIRA: https://issues.apache.org/jira/browse/ARROW-11723

None

[Jefffrey]

I'll close as not doing this; we have a config to change dialect to postgres if users need that functionality:

datafusion/datafusion/common/src/config.rs

Lines 259 to 261 in 621a249

	/// 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.
	pub dialect: Dialect, default = Dialect::Generic