Refactor codebase to import join module and use it in place of indivi…

…dual join types

Refactor codebase to add support for full join in SQL queries
Refactor codebase to optimize execution of logical plans and improve aggregation functionality

qurious/src/execution/session.rs

@@ -253,10 +253,17 @@ mod tests {
     #[test]
     fn test_create_table() -> Result<()> {
         let session = ExecuteSession::new()?;
-        session.sql("create table t(v1 int, v2 int);")?;
-        session.sql("insert into t values (1, 1), (null, 2), (null, 3), (4, 4);")?;
+        session.sql("create table a(v1 int, v2 int);")?;
+        session.sql("create table b(v3 int, v4 int);")?;
 
-        let batch = session.sql("select v2 from t where v1 is null")?;
+        // session.sql("create table x(a int, b int);")?;
+        // session.sql("create table y(c int, d int);")?;
+
+        session.sql("insert into a values (1, 1), (2, 2), (3, 3);")?;
+        session.sql("insert into b values (1, 100), (3, 300), (4, 400);")?;
+
+        let batch = session.sql("select v1, v2, v3, v4 from a full join b on v1 = v3;")?;
+        // let batch = session.sql("select 1 > null")?;
 
         print_batches(&batch)?;