database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-12-24 11:21:21 +03:00
Code Activity

Fix for bug #31249: Assertion `!table || (!table->write_set ||

Browse Source 
bitmap_is_set(table->write_set, fiel

Problem: creating a temporary table we allocate the group buffer if needed
followed by table bitmaps (see create_tmp_table()). Reserving less memory for 
the group buffer than actually needed (used) for values retrieval may lead 
to overlapping with followed bitmaps in the memory pool that in turn leads 
to unpredictable consequences.

As we use Item->max_length sometimes to calculate group buffer size,
it must be set to proper value. In this particular case 
Item_datetime_typecast::max_length is too small.

Another problem is that we use max_length to calculate the group buffer
key length for items represented as DATE/TIME fields which is superfluous.

Fix: set Item_datetime_typecast::max_length properly,
accurately calculate the group buffer key length for items 
represented as DATE/TIME fields in the buffer.


mysql-test/r/type_datetime.result:
  Fix for bug #31249: Assertion `!table || (!table->write_set || 
  bitmap_is_set(table->write_set, fiel
    - test result.
mysql-test/t/type_datetime.test:
  Fix for bug #31249: Assertion `!table || (!table->write_set || 
  bitmap_is_set(table->write_set, fiel
    - test case.
sql/item_timefunc.h:
  Fix for bug #31249: Assertion `!table || (!table->write_set || 
  bitmap_is_set(table->write_set, fiel
    - set Item_datetime_typecast::max_length properly.
sql/sql_select.cc:
  Fix for bug #31249: Assertion `!table || (!table->write_set || 
  bitmap_is_set(table->write_set, fiel
    - the group buffer key length for items represented as 
  DATE/TIME fields in the buffer should be calculated using
  the maximum pack length of such fields (== 8), using 
  max_length here is redundant.
This commit is contained in:
unknown
2007-10-09 14:37:21 +05:00
parent 6dc4dfb363
commit 1a5f13a12c
4 changed files with 52 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
sql/sql_select.cc
View File

@@ -13902,13 +13902,31 @@ calc_group_buffer(JOIN *join,ORDER *group)
group_item->decimals);
break;
case STRING_RESULT:
{
enum enum_field_types type= group_item->field_type();
/*
Group strings are taken as varstrings and require an length field.
A field is not yet created by create_tmp_field()
and the sizes should match up.
As items represented as DATE/TIME fields in the group buffer
have STRING_RESULT result type, we increase the length
by 8 as maximum pack length of such fields.
*/
key_length+= group_item->max_length + HA_KEY_BLOB_LENGTH;
if (type == MYSQL_TYPE_TIME ||
type == MYSQL_TYPE_DATE ||
type == MYSQL_TYPE_DATETIME ||
type == MYSQL_TYPE_TIMESTAMP)
{
key_length+= 8;
}
else
{
/*
Group strings are taken as varstrings and require an length field.
A field is not yet created by create_tmp_field()
and the sizes should match up.
*/
key_length+= group_item->max_length + HA_KEY_BLOB_LENGTH;
}
break;
}
default:
/* This case should never be choosen */
DBUG_ASSERT(0);