From 1b31fd3bdb5e7ca92cbad5b019e128d58b50703a Mon Sep 17 00:00:00 2001
From: Leonid Fedorov <79837786+mariadb-LeonidFedorov@users.noreply.github.com>
Date: Thu, 27 Jun 2024 14:20:23 +0400
Subject: [PATCH] fix(plugin) MCOL-5699: throw error for unimplemented
 INTERSECT and EXCEPT (#3219)

---
 dbcon/mysql/ha_mcs_execplan.cpp               | 20 +++++++++
 .../columnstore/bugfixes/MCOL-5699.result     | 43 +++++++++++++++++++
 .../columnstore/bugfixes/MCOL-5699.test       | 40 +++++++++++++++++
 3 files changed, 103 insertions(+)
 create mode 100644 mysql-test/columnstore/bugfixes/MCOL-5699.result
 create mode 100644 mysql-test/columnstore/bugfixes/MCOL-5699.test

diff --git a/dbcon/mysql/ha_mcs_execplan.cpp b/dbcon/mysql/ha_mcs_execplan.cpp
index a99d07a25..8b3e2ca94 100644
--- a/dbcon/mysql/ha_mcs_execplan.cpp
+++ b/dbcon/mysql/ha_mcs_execplan.cpp
@@ -6830,6 +6830,26 @@ int processFrom(bool& isUnion, SELECT_LEX& select_lex, gp_walk_info& gwi, SCSEP&
   // Existed pushdown handlers won't get in this scope
   // MDEV-25080 Union pushdown would enter this scope
   // is_unit_op() give a segv for derived_handler's SELECT_LEX
+
+  // check INTERSECT or EXCEPT, that are not implemented
+  if (select_lex.master_unit() && select_lex.master_unit()->first_select())
+  {
+    for (auto nextSelect = select_lex.master_unit()->first_select()->next_select(); nextSelect;
+         nextSelect = nextSelect->next_select())
+    {
+      if (nextSelect->get_linkage() == INTERSECT_TYPE)
+      {
+        setError(gwi.thd, ER_INTERNAL_ERROR, "INTERSECT is not supported by Columnstore engine", gwi);
+        return ER_INTERNAL_ERROR;
+      }
+      else if (nextSelect->get_linkage() == EXCEPT_TYPE)
+      {
+        setError(gwi.thd, ER_INTERNAL_ERROR, "EXCEPT is not supported by Columnstore engine", gwi);
+        return ER_INTERNAL_ERROR;
+      }
+    }
+  }
+
   if (!isUnion && (!isSelectHandlerTop || isSelectLexUnit) && select_lex.master_unit()->is_unit_op())
   {
     // MCOL-2178 isUnion member only assigned, never used
diff --git a/mysql-test/columnstore/bugfixes/MCOL-5699.result b/mysql-test/columnstore/bugfixes/MCOL-5699.result
new file mode 100644
index 000000000..a90b3560a
--- /dev/null
+++ b/mysql-test/columnstore/bugfixes/MCOL-5699.result
@@ -0,0 +1,43 @@
+DROP DATABASE IF EXISTS mcol_5699 ;
+CREATE DATABASE mcol_5699 ;
+USE mcol_5699 ;
+CREATE TABLE cs1(a text) ENGINE=columnstore;
+INSERT INTO cs1 VALUES('a'),('b'),('c'),('x');
+CREATE TABLE cs2(a text) ENGINE=columnstore;
+INSERT INTO cs2 VALUES('y'),('z'),('x');
+CREATE TABLE cs3(a text) ENGINE=columnstore;
+INSERT INTO cs3 VALUES('r'),('t'),('z');
+SELECT a from cs1 UNION ALL select a from cs2;
+a
+a
+b
+c
+x
+x
+y
+z
+SELECT a from cs1 UNION DISTINCT select a from cs2;
+a
+a
+b
+c
+x
+y
+z
+SELECT a from cs1 INTERSECT ALL select a from cs2;
+ERROR HY000: Internal error: INTERSECT is not supported by Columnstore engine
+SELECT a from cs1 INTERSECT DISTINCT select a from cs2;
+ERROR HY000: Internal error: INTERSECT is not supported by Columnstore engine
+SELECT a from cs1 EXCEPT ALL select a from cs2;
+ERROR HY000: Internal error: EXCEPT is not supported by Columnstore engine
+SELECT a from cs1 EXCEPT DISTINCT select a from cs2;
+ERROR HY000: Internal error: EXCEPT is not supported by Columnstore engine
+SELECT a from cs1 UNION select a from cs2 INTERSECT ALL select a from cs3;
+ERROR HY000: Internal error: INTERSECT is not supported by Columnstore engine
+SELECT a from cs1 UNION select a from cs2 INTERSECT DISTINCT select a from cs3;
+ERROR HY000: Internal error: INTERSECT is not supported by Columnstore engine
+SELECT a from cs1 UNION select a from cs2 EXCEPT ALL select a from cs3;
+ERROR HY000: Internal error: EXCEPT is not supported by Columnstore engine
+SELECT a from cs1 UNION select a from cs2 EXCEPT DISTINCT select a from cs3;
+ERROR HY000: Internal error: EXCEPT is not supported by Columnstore engine
+DROP DATABASE mcol_5699 ;
diff --git a/mysql-test/columnstore/bugfixes/MCOL-5699.test b/mysql-test/columnstore/bugfixes/MCOL-5699.test
new file mode 100644
index 000000000..c5614a2c2
--- /dev/null
+++ b/mysql-test/columnstore/bugfixes/MCOL-5699.test
@@ -0,0 +1,40 @@
+--source ../include/have_columnstore.inc
+--disable_warnings
+DROP DATABASE IF EXISTS mcol_5699 ;
+--enable_warnings
+CREATE DATABASE mcol_5699 ;
+USE mcol_5699 ;
+CREATE TABLE cs1(a text) ENGINE=columnstore;
+INSERT INTO cs1 VALUES('a'),('b'),('c'),('x');
+
+CREATE TABLE cs2(a text) ENGINE=columnstore;
+INSERT INTO cs2 VALUES('y'),('z'),('x');
+
+CREATE TABLE cs3(a text) ENGINE=columnstore;
+INSERT INTO cs3 VALUES('r'),('t'),('z');
+
+--sorted_result
+SELECT a from cs1 UNION ALL select a from cs2;
+--sorted_result
+SELECT a from cs1 UNION DISTINCT select a from cs2;
+
+--ERROR 1815
+SELECT a from cs1 INTERSECT ALL select a from cs2;
+--ERROR 1815
+SELECT a from cs1 INTERSECT DISTINCT select a from cs2;
+--ERROR 1815
+SELECT a from cs1 EXCEPT ALL select a from cs2;
+--ERROR 1815
+SELECT a from cs1 EXCEPT DISTINCT select a from cs2;
+
+--ERROR 1815
+SELECT a from cs1 UNION select a from cs2 INTERSECT ALL select a from cs3;
+--ERROR 1815
+SELECT a from cs1 UNION select a from cs2 INTERSECT DISTINCT select a from cs3;
+--ERROR 1815
+SELECT a from cs1 UNION select a from cs2 EXCEPT ALL select a from cs3;
+--ERROR 1815
+SELECT a from cs1 UNION select a from cs2 EXCEPT DISTINCT select a from cs3;
+
+
+DROP DATABASE mcol_5699 ;