MDEV-4978 - Server cursor is broken with blobs in the select list,

            ORDER BY does not work

Use "dynamic" row format (instead of "block") for MARIA internal
temporary tables created for cursors.

With "block" row format MARIA may shuffle rows, with "dynamic" row
format records are inserted sequentially (there are no gaps in data
file while we fill temporary tables).

This is needed to preserve row order when scanning materialized cursors.

1 files changed, 4 insertions, 2 deletions

diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 1551a8ff6d6..8a5ec26ba80 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -129,6 +129,7 @@ bool select_union::flush()
       table_alias        name of the temporary table
       bit_fields_as_long convert bit fields to ulonglong
       create_table       whether to physically create result table
+      keep_row_order     keep rows in order as they were inserted
 
   DESCRIPTION
     Create a temporary table that is used to store the result of a UNION,
@@ -143,7 +144,8 @@ bool
 select_union::create_result_table(THD *thd_arg, List<Item> *column_types,
                                   bool is_union_distinct, ulonglong options,
                                   const char *alias,
-                                  bool bit_fields_as_long, bool create_table)
+                                  bool bit_fields_as_long, bool create_table,
+                                  bool keep_row_order)
 {
   DBUG_ASSERT(table == 0);
   tmp_table_param.init();
@@ -153,7 +155,7 @@ select_union::create_result_table(THD *thd_arg, List<Item> *column_types,
   if (! (table= create_tmp_table(thd_arg, &tmp_table_param, *column_types,
                                  (ORDER*) 0, is_union_distinct, 1,
                                  options, HA_POS_ERROR, alias,
-                                 !create_table)))
+                                 !create_table, keep_row_order)))
     return TRUE;
 
   table->keys_in_use_for_query.clear_all();