when executed in version 5
Zero fill is a field attribute only. So we can't always
propagate constants for zerofill fields : the values and
expression results don't have that flag.
Fixed by converting the const value to a string and
using that in const propagation when the context allows it.
Disable const propagation for fields with ZEROFILL flag in
all the other cases.
for wildcard values.
The server ignored escape character before wildcards during
the calculation of priority values for sorting of a privilege
list. (Actually the server counted an escape character as an
ordinary wildcard like % or _). I.e. the table name template
with a wildcard character like 'tbl_1' had higher priority in
a privilege list than concrete table name without wildcards
like 'tbl\_1', and some privileges of 'tbl\_1' was hidden
by privileges for 'tbl_1'.
The get_sort function has been modified to ignore escaped
wildcards as usual.
type conversion.
Instead of copying of whole character string from a temporary
buffer, the server copied a short-living pointer to that string
into a long-living structure. That has been fixed.
or trigger crashes server
Under some circumstances a combination of VIEWs, subselects with outer
references and PS/SP/triggers could lead to use of uninitialized memory
and server crash as a result.
Fixed by changing the code in Item_field::fix_fields() so that in cases
when the field is a VIEW reference, we first check whether the field
is also an outer reference, and mark it appropriately before returning.
Field data for a query was stored to the stmt->alloc that is emptied
with mysql_stmt_close statement only. That means a lot of memory can
be occupied without a reason if used doesn't call mysql_stmt_close often.
The out of memory error was thrown when the sort buffer size were too small.
This led to a user confusion.
Now filesort throws the error message about sort buffer being too small.
The bug was that handler::clone/handler::ha_open() call caused allocation of
cloned_copy->ref on the handler->table->mem_root. The allocated memory could not
be reclaimed until the table is flushed, so it was possible to exhaust memory by
repeatedly running index_merge queries without doing table flushes.
The fix:
- make handler::clone() allocate new_handler->ref on the passed mem_root
- make handler::ha_open() not allocate this->ref if it has already been allocated
There is no testcase as it is not possible to check small leaks from testsuite.
and my_innodb_commit_concurrency global variables.
Type of the my_innodb_autoextend_increment and the
my_innodb_commit_concurrency variables has been changed to
GET_ULONG.
Server handles truncation for assignment of too-long values
into CHAR/VARCHAR/TEXT columns in a different ways when the
truncated characters are spaces:
1. CHAR(N) columns silently ignore end-space truncation;
2. TEXT columns post a truncation warning/error in the
non-strict/strict mode.
3. VARCHAR columns always post a truncation note in
any mode.
Space truncation processing has been synchronised over
CHAR/VARCHAR/TEXT columns: current behavior of VARCHAR
columns has been propagated as standard.
Binary-encoded string/BLOB columns are not affected.
on table creates
The problem was in incompatible syntax for key definition in CREATE
TABLE.
5.0 supports only the following syntax for key definition (see "CREATE
TABLE syntax" in the manual):
{INDEX|KEY} [index_name] [index_type] (index_col_name,...)
While 5.1 parser supports the above syntax, the "preferred" syntax was
changed to:
{INDEX|KEY} [index_name] (index_col_name,...) [index_type]
The above syntax is used in 5.1 for the SHOW CREATE TABLE output, which
led to dumps generated by 5.1 being incompatible with 5.0.
Fixed by changing the parser in 5.0 to support both 5.0 and 5.1 syntax
for key definition.
Simple subselects are pulled into upper selects. This operation substitutes the
pulled subselect for the first item from the select list of the subselect.
If an alias is defined for a subselect it is inherited by the replacement item.
As this is done after fix_fields phase this alias isn't showed if the
replacement item is a stored function. This happens because the Item_func_sp::make_field
function makes send field from its result_field and ignores the defined alias.
Now when an alias is defined the Item_func_sp::make_field function sets it for
the returned field.
