MDEV-19632 Replication aborts with ER_SLAVE_CONVERSION_FAILED upon CREATE ... SELECT in ORACLE mode

- Adding optional qualifiers to data types:
    CREATE TABLE t1 (a schema.DATE);
  Qualifiers now work only for three pre-defined schemas:

    mariadb_schema
    oracle_schema
    maxdb_schema

  These schemas are virtual (hard-coded) for now, but may turn into real
  databases on disk in the future.

- mariadb_schema.TYPE now always resolves to a true MariaDB data
  type TYPE without sql_mode specific translations.

- oracle_schema.DATE translates to MariaDB DATETIME.

- maxdb_schema.TIMESTAMP translates to MariaDB DATETIME.

- Fixing SHOW CREATE TABLE to use a qualifier for a data type TYPE
  if the current sql_mode translates TYPE to something else.

The above changes fix the reported problem, so this script:

    SET sql_mode=ORACLE;
    CREATE TABLE t2 AS SELECT mariadb_date_column FROM t1;

is now replicated as:

    SET sql_mode=ORACLE;
    CREATE TABLE t2 (mariadb_date_column mariadb_schema.DATE);

and the slave can unambiguously treat DATE as the true MariaDB DATE
without ORACLE specific translation to DATETIME.

Similar,

    SET sql_mode=MAXDB;
    CREATE TABLE t2 AS SELECT mariadb_timestamp_column FROM t1;

is now replicated as:

    SET sql_mode=MAXDB;
    CREATE TABLE t2 (mariadb_timestamp_column mariadb_schema.TIMESTAMP);

so the slave treats TIMESTAMP as the true MariaDB TIMESTAMP
without MAXDB specific translation to DATETIME.

1 files changed, 5 insertions, 0 deletions

diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 8b8a55e0c96..55929ed7df6 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -32,6 +32,7 @@
 #include "sp.h"                       // enum stored_procedure_type
 #include "sql_tvc.h"
 #include "item.h"
+#include "sql_schema.h"
 
 /* Used for flags of nesting constructs */
 #define SELECT_NESTING_MAP_SIZE 64
@@ -2144,6 +2145,7 @@ private:
 struct st_parsing_options
 {
   bool allows_variable;
+  bool lookup_keywords_after_qualifier;
 
   st_parsing_options() { reset(); }
   void reset();
@@ -4052,6 +4054,9 @@ public:
   bool tvc_finalize();
   bool tvc_finalize_derived();
 
+  bool map_data_type(const Lex_ident_sys_st &schema,
+                     Lex_field_type_st *type) const;
+
   void mark_first_table_as_inserting();
 };