Hi Varun, First reaction:
diff --git a/sql/sql_table.cc b/sql/sql_table.cc index 84e4018..63636f9 100644 --- a/sql/sql_table.cc +++ b/sql/sql_table.cc @@ -3948,7 +3948,11 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info, key_part_info->fieldnr= field; key_part_info->offset= (uint16) sql_field->offset; key_part_info->key_type=sql_field->pack_flag; - uint key_part_length= sql_field->key_length; + uint key_part_length= MY_MAX(sql_field->key_length, + sql_field->pack_length);
What does the above do? It is not clear why MAX should be used. (Let's denote the compared variables X and Y. Can X>Y and X<Y both happen in practice? This requires a comment!)
+ + if (!(sql_field->flags & NOT_NULL_FLAG)) + key_part_length++;
if (column->length) {
I am concerned that the above may have an undesired effect: key_part_kength counts NULL-byte while previously it did not. Let's try this example: create table t1 (pk int not null primary key, col1 int, key(col1) ) engine=innodb; Run it, and put a breakpoint below on this code: /* Check if the key segment is partial, set the key flag accordingly */ if (key_part_length != sql_field->key_length) key_info->flags|= HA_KEY_HAS_PART_KEY_SEG; You will see that for filed 'col1' HA_KEY_HAS_PART_KEY_SEG flag is now set. This didn't happen before. Is this really intended? I wasn't able to find what exactly may get wrong, but if I run this query: explain select * from t1 where col1=1; then it hangs. BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://s.petrunia.net/blog