In commit 1811fd51fb the assertion
should have said error_reported instead of !error_reported.
But, that revised assertion would still fail in main.defaults
where ER_BAD_DATA is reported during CREATE TABLE.
This is a duplicate of MDEV-18278 89936f11e9, but I will add an
additional assertion
Description:
The frm corruption should not be reported during CREATE TABLE. Normally
it doesn't, and the data to fill TABLE is taken by open_table_from_share
call. However, the vcol data is stored as SQL string in
table->s->vcol_defs.str and is anyway parsed on each table open.
It is impossible [or hard] to avoid, because it's hard to clone the
expression tree in general (it's easier to parse).
Normally parse_vcol_defs should only fail on semantic errors. If so,
error_reported is set to true. Any other failure is not expected during
table creation. There is either unhandled/unacknowledged error, or
something went really wrong, like memory reject. This all should be
asserted anyway.
Solution:
* Set *error_reported=true for the forward references check;
* Assert for every unacknowledged error during table creation.
There were two independent problems which lead to the crash
and to the non-relevant records returned in I_S queries:
- The code in the I_S implementation was not secure
about values with 0x00 bytes.
It's fixed by using check_db_name() and check_table_name()
inside make_table_name_list(), and by adding the test for
0x00 inside check_table_name().
- The code in Item_string::print() did not convert
strings without introducers when restoring
the CREATE VIEW statement from an Item tree.
This made wrong literals inside the "query" line in the view FRM file
in cases when the VIEW parse time
character_set_client!=character_set_connection.
That's fixed by adding a proper conversion.
This change also fixed a similar problem in SHOW PROCEDURE CODE -
the literals were displayed in wrong character set in SP instructions
in cases when the SP parse time
character_set_client!=character_set_connection.
in about a hundred of users of MY_BITMAP, only two were using its
built-in mutex, and only one of those two was actually needing it.
Remove the mutex from MY_BITMAP, remove all associated conditions
and checks in bitmap functions. Use an external LOCK_temp_pool
mutex and temp_pool_set_next/temp_pool_clear_bit acccessors.
Remove bitmap_init/bitmap_free, always use my_* versions.
Server crashes in Field::register_field_in_read_map upon select from
partitioned table with indexed by prefix virtual column.
After several read-mark fixes a problem has surfaced:
Since KEY (c(10),a) uses only a prefix of c, a new field is created,
duplicated from table->field[3], with a new length. However,
vcol_inco->expr is not copied.
Therefore, (*key_info)->key_part[i].field->vcol_info->expr was left NULL
in ha_partition::index_init().
Solution: copy vcol_info from table field when it's set up.
Server crashes in Field::register_field_in_read_map upon select from
partitioned table with indexed by prefix virtual column.
After several read-mark fixes a problem has surfaced:
Since KEY (c(10),a) uses only a prefix of c, a new field is created,
duplicated from table->field[3], with a new length. However,
vcol_inco->expr is not copied.
Therefore, (*key_info)->key_part[i].field->vcol_info->expr was left NULL
in ha_partition::index_init().
Solution: initialize vcols before key initialization
Also key initialization is moved to a function.
Reformulate mark_columns_used_by_index* function family in a more laconic
way:
mark_columns_used_by_index -> mark_index_columns
mark_columns_used_by_index_for_read_no_reset -> mark_index_columns_for_read
mark_columns_used_by_index_no_reset -> mark_index_columns_no_reset
static mark_index_columns -> do_mark_index_columns
Several different test cases were failing under the same reason: the
fields in a vcol expression were not marked during marking columns of a key
contatining virtual column for read.
Fix: make marking columns of a key for read a special case where
register_field_in_read_map() is done instead of plain bitmap_set_bit().
Some test cases are only reproducible in 10.4+, but the fix is applicable
to 10.2+
This is a 10.2+ part of a jira task
The two bugs regarding virtual column marking have been fixed:
1. UPDATE of a partitioned table, where the optimizer has chosen a
secondary index to make a filesort;
2. INSERT into a table with a nonblob field generated from a blob, with
binlog enabled and binlog_row_image=noblob.
3. DELETE from a view on a table with virtual column.
Generally the assertion happens from update_virtual_fields() call
These bugs are root-caused by missing field marking for dependant fields
of a virtual column.
Therefore a fix is: mark all the fields involved in the vcol expression by
calling field->register_field_in_read_map() instead just setting a single
bit.
3 was reproducible only on 10.4+, however the problem might has just been
invisible in the earlier versions. The fix is applicable to 10.2-10.3 as
well.
We cannot revert the ALTER, so anything happening after
the point of no return should not be treated as an error. A
very unfortunate condition that a user needs to be warned about - yes,
but we cannot say "ALTER TABLE has failed" if the table was successfully
altered.
This replaces 8711adb786
if a temptable field is created for some json expression (is_json_type()
returns true), make this temptable field a proper json field.
A field is a json field (see Item_field::is_json_type()) if it
has a CHECK constraint of JSON_VALID(field).
Note that it will never be actually checked for temptable fields,
so it won't cause a run-time slowdown.
The ROWNUM() function is for SELECT mapped to JOIN->accepted_rows, which is
incremented for each accepted rows.
For Filesort, update, insert, delete and load data, we map ROWNUM() to
internal variables incremented when the table is changed.
The connection between the row counter and Item_func_rownum is done
in sql_select.cc::fix_items_after_optimize() and
sql_insert.cc::fix_rownum_pointers()
When ROWNUM() is used anywhere in query, the optimization to ignore ORDER
BY in sub queries are disabled. This was done to get the following common
Oracle query to work:
select * from (select * from t1 order by a desc) as t where rownum() <= 2;
MDEV-3926 "Wrong result with GROUP BY ... WITH ROLLUP" contains a discussion
about this topic.
LIMIT optimization is enabled when in a top level WHERE clause comparing
ROWNUM() with a numerical constant using any of the following expressions:
- ROWNUM() < #
- ROWNUM() <= #
- ROWNUM() = 1
ROWNUM() can be also be the right argument to the comparison function.
LIMIT optimization is done in two cases:
- For the current sub query when the ROWNUM comparison is done on the top
level:
SELECT * from t1 WHERE rownum() <= 2 AND t1.a > 0
- For an inner sub query, when the upper level has only a ROWNUM comparison
in the WHERE clause:
SELECT * from (select * from t1) as t WHERE rownum() <= 2
In Oracle mode, one can also use ROWNUM without parentheses.
Other things:
- Fixed bug where the optimizer tries to optimize away sub queries
with RAND_TABLE_BIT set (non-deterministic queries). Now these
sub queries will not be converted to joins. This bug fix was also
needed to get rownum() working inside subqueries.
- In remove_const() remove setting simple_order to FALSE if ROLLUP is
USED. This code was disable a long time ago because of wrong assignment
in the following code. Instead we set simple_order to false if
RAND_TABLE_BIT was used in the SELECT list. This ensures that
we don't delete ORDER BY if the result set is not deterministic, like
in 'SELECT RAND() AS 'r' FROM t1 ORDER BY r';
- Updated parameters for Sort_param::init_for_filesort() to be able
to provide filesort with information where the number of accepted
rows should be stored
- Reordered fields in class Filesort to optimize storage layout
- Added new error messsage to tell that a function can't be used in HAVING
- Added field 'with_rownum' to THD to mark that ROWNUM() is used in the
query.
Co-author: Oleksandr Byelkin <sanja@mariadb.com>
LIMIT optimization for sub query
- Moved out creating StringBuffers in loops and instead create them
outside and just reset the buffer if it was not allocated (to avoid
a possible malloc/free for every entry)
Other things related to set_buffer_if_not_allocated()
- Changed Valuebuffer to not call set_buffer_if_not_allocated() when
it is created.
- Fixed geometry functions to reset string length before calling
String::reserve(). This is because one should not access length()
of an undefined.
- Added Item_func_conv_charset::save_in_field() as the item is using
str_value to store cached values, which conflicts with
Item::save_str_in_field().
- Changed Item_proc_string to not store the string value in sql_string
as this clashes with Item::save_str_in_field().
- Locally store value of full_name_cstring() in analyse::end_of_records()
as Item::save_str_in_field() may overwrite it.
- Marked some strings as set_thread_specific()
- Added String::free_buffer() to be used internally in String functions
to just free the buffer but not reset other String values.
- Fixed uses_buffer_owned_by() to check for allocated length instead of
strlength, which could be marked MEM_UNDEFINED().
This change removed 68 explict strlen() calls from the code.
The following renames was done to ensure we don't use the old names
when merging code from earlier releases, as using the new variables
for print function could result in crashes:
- charset->csname renamed to charset->cs_name
- charset->name renamed to charset->coll_name
Almost everything where mechanical changes except:
- Changed to use the new Protocol::store(LEX_CSTRING..) when possible
- Changed to use field->store(LEX_CSTRING*, CHARSET_INFO*) when possible
- Changed to use String->append(LEX_CSTRING&) when possible
Other things:
- There where compiler issues with ensuring that all character set names
points to the same string: gcc doesn't allow one to use integer constants
when defining global structures (constant char * pointers works fine).
To get around this, I declared defines for each character set name
length.
Changes:
- To detect automatic strlen() I removed the methods in String that
uses 'const char *' without a length:
- String::append(const char*)
- Binary_string(const char *str)
- String(const char *str, CHARSET_INFO *cs)
- append_for_single_quote(const char *)
All usage of append(const char*) is changed to either use
String::append(char), String::append(const char*, size_t length) or
String::append(LEX_CSTRING)
- Added STRING_WITH_LEN() around constant string arguments to
String::append()
- Added overflow argument to escape_string_for_mysql() and
escape_quotes_for_mysql() instead of returning (size_t) -1 on overflow.
This was needed as most usage of the above functions never tested the
result for -1 and would have given wrong results or crashes in case
of overflows.
- Added Item_func_or_sum::func_name_cstring(), which returns LEX_CSTRING.
Changed all Item_func::func_name()'s to func_name_cstring()'s.
The old Item_func_or_sum::func_name() is now an inline function that
returns func_name_cstring().str.
- Changed Item::mode_name() and Item::func_name_ext() to return
LEX_CSTRING.
- Changed for some functions the name argument from const char * to
to const LEX_CSTRING &:
- Item::Item_func_fix_attributes()
- Item::check_type_...()
- Type_std_attributes::agg_item_collations()
- Type_std_attributes::agg_item_set_converter()
- Type_std_attributes::agg_arg_charsets...()
- Type_handler_hybrid_field_type::aggregate_for_result()
- Type_handler_geometry::check_type_geom_or_binary()
- Type_handler::Item_func_or_sum_illegal_param()
- Predicant_to_list_comparator::add_value_skip_null()
- Predicant_to_list_comparator::add_value()
- cmp_item_row::prepare_comparators()
- cmp_item_row::aggregate_row_elements_for_comparison()
- Cursor_ref::print_func()
- Removes String_space() as it was only used in one cases and that
could be simplified to not use String_space(), thanks to the fixed
my_vsnprintf().
- Added some const LEX_CSTRING's for common strings:
- NULL_clex_str, DATA_clex_str, INDEX_clex_str.
- Changed primary_key_name to a LEX_CSTRING
- Renamed String::set_quick() to String::set_buffer_if_not_allocated() to
clarify what the function really does.
- Rename of protocol function:
bool store(const char *from, CHARSET_INFO *cs) to
bool store_string_or_null(const char *from, CHARSET_INFO *cs).
This was done to both clarify the difference between this 'store' function
and also to make it easier to find unoptimal usage of store() calls.
- Added Protocol::store(const LEX_CSTRING*, CHARSET_INFO*)
- Changed some 'const char*' arrays to instead be of type LEX_CSTRING.
- class Item_func_units now used LEX_CSTRING for name.
Other things:
- Fixed a bug in mysql.cc:construct_prompt() where a wrong escape character
in the prompt would cause some part of the prompt to be duplicated.
- Fixed a lot of instances where the length of the argument to
append is known or easily obtain but was not used.
- Removed some not needed 'virtual' definition for functions that was
inherited from the parent. I added override to these.
- Fixed Ordered_key::print() to preallocate needed buffer. Old code could
case memory overruns.
- Simplified some loops when adding char * to a String with delimiters.
This was done to simplify copying of with_* flags
Other things:
- Changed Flags to C++ enums, which enables gdb to print
out bit values for the flags. This also enables compiler
errors if one tries to manipulate a non existing bit in
a variable.
- Added set_maybe_null() as a shortcut as setting the
MAYBE_NULL flags was used in a LOT of places.
- Renamed PARAM flag to SP_VAR to ensure it's not confused with persistent
statement parameters.
One should instead use Item::fixed() and Item::with_subquery()
Removed Item::is_fixed() and has_subquery() and did the following replace:
replace is_fixed() fixed() -- *.*
replace 'has_subquery()' 'with_subquery()' -- *.*
The reason for the change is that neither clang or gcc can do efficient
code when several bit fields are change at the same time or when copying
one or more bits between identical bit fields.
Updated bits explicitely with & and | is MUCH more efficient than what
current compilers can do.
The problem was that when one used String::alloc() to allocate a string,
the String ensures that there is space for an extra NULL byte in the
buffer and if not, reallocates the string. This is a problem with the
String::set_int() that calls alloc(21), which forces extra
malloc/free calls to happen.
- We do not anymore re-allocate String if alloc() is called with the
Allocated_length. This reduces number of malloc() allocations,
especially one big re-allocation in Protocol::send_result_Set_metadata()
for almost every query that produced a result to the connnected client.
- Avoid extra mallocs when using LONGLONG_BUFFER_SIZE
This can now be done as alloc() doesn't increase buffers if new length is
not bigger than old one.
- c_ptr() is redesigned to be safer (but a bit longer) than before.
- Remove wrong usage of c_ptr_quick()
c_ptr_quick() was used in many cases to get the pointer to the used
buffer, even when it didn't need to be \0 terminated. In this case
ptr() is a better substitute.
Another problem with c_ptr_quick() is that it did not guarantee that
the string would be \0 terminated.
- item_val_str(), an API function not used currently by the server,
now always returns a null terminated string (before it didn't always
do that).
- Ensure that all String allocations uses STRING_PSI_MEMORY_KEY. The old
mixed usage of performance keys caused assert's when String buffers
where shrunk.
- Binary_string::shrink() is simplifed
- Fixed bug in String(const char *str, size_t len, CHARSET_INFO *cs) that
used Binary_string((char *) str, len) instead of Binary_string(str,len).
- Changed argument to String() creations and String.set() functions to use
'const char*' instead of 'char*'. This ensures that Alloced_length is
not set, which gives safety against someone trying to change the
original string. This also would allow us to use !Alloced_length in
c_ptr() if needed.
- Changed string_ptr_cmp() to use memcmp() instead of c_ptr() to avoid
a possible malloc during string comparision.
This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.
