crashes server (prepared statements)": the bug was that all boolean
items always recovered its original arguments at statement cleanup
stage.
This collided with Item_subselect::select_transformer, which tries to
permanently change the item tree to use a transformed subselect instead of
original one.
So we had this call sequence for prepare:
mysql_stmt_prepare -> JOIN::prepare ->
Item_subselect::fix_fields -> the item tree gets transformed ->
Item_bool_rowready_func2::cleanup, item tree is recovered to original
state, while it shouldn't have been;
mysql_stmt_execute -> attempts to execute a broken tree -> crash.
Now instead of bluntly recovering all arguments of bool functions in
Item_bool_rowready_func2::cleanup, we recover only those
which were changed, and do it in one place.
There still would exist a possibility for a collision with subselect
tranformation, if permanent and temporary changes were performed at the
same stage.
But fortunately subselect transformation is always done first, so it
doesn't conflict with the optimization done by propogate_cond_constants.
Now we have:
mysql_stmt_prepare -> JOIN::prepare -> subselect transformation
permanently changes the tree -> cleanup doesn't recover anything,
because nothing was registered for recovery.
mysql_stmt_execute -> JOIN::prepare (the tree is already transformed,
so it doesn't change), JOIN::optimize ->
propogate_cond_constants -> temporary changes the item tree
with constants -> JOIN::execute -> cleanup ->
the changes done by propogate_cond_constants are recovered, as
they were registered for recovery.
crashes mysqld": implementation for a generic item tree modifications
registry. Every item tree modification which should be rolled back for
subsequent execution of a prepared statement or stored procedure should
be saved in the registry. All such modifications are rolled back at once
during cleanup stage of PS.
Actual fix for the bug just adds a call to register modifications to
convert_constant_item.
Post review fixes implemented.
character set introducer": add new item type to be returned before from
Item_param until it's value is set.
This way items like Item_bool_func2 and udf_handler won't treat this item
as constant literal when statement is prepared.
after Monty's review.
- Item_param was rewritten.
- it turns out that we can't convert string data to character set of
connection on the fly, because they first should be written to the binary
log.
To support efficient conversion we need to rewrite prepared statements
binlogging code first.
"mysql_send_long_data() API call is completely broken".
Now we are resetting some members (long_data_supplied/null_value...) of Item_param to its
initial state after each execution of prepared statement. We also manipulating
Item_param::maybe_null/null_value only via Item_param::set_* setters which makes code a bit
more robust.
table resolution".
Added members to Item_ident for storing original db, table and field
names since those that set later from Field have shorter life-time
than required by prep. stmt. So we need to restore original names in
Item_ident::cleanup(). Also now using special construnctor for creation
of Item_field from Field object that ensures that table and field name
have big enough life-time.
"Fix" for bug #2050 "10 to 1 performance drop with server 4.1.1"
Clean ups in implementation of caching of field number in table.
Added caching of table in which field is found in find_field_in_tables().
Actually it is not a bug but right behavior observed as pefomance
degradation after we have forced Item_field::fix_fields() to
re-execute each time when we are executing prep stmt.
This patch implements small optimization which heals this bad
behavior. We are caching field position in TABLE::field array in
Item's member and are using this position for speeding up field
lookups in fix_fields() in case of its re-execution.
COM_EXECUTE packet" and #2795 "prepare + execute without bind_param crashes
server" and #2473 "seg fault running tests/client_test.c":
- length checking added to packet parser
- default impelemntation of Item_param::set_param_func will work in
case of malformed packet.
No test cases are possible in our test suite, as there are no tests
operating on protocol layer.
Cleaned up embedded library access and query cache handling
Changed min stack size to 128K (to allow longer MyISAM keys)
Fixed wrong priority for XOR (should be less than NEG to get -1^1 to work)
Don't dump data for MRG_ISAM or MRG_MYISAM tables. (Bug #1846)
Ensure that 'lower_case_table_names' is always set on case insensitive file systems. (Bug #1812)
One can now configure MySQL as windows service as a normal user. (Bug #1802)
Database names is now compared with lower case in ON clause when lower_case_table_names is set. (Bug #1736)
IGNORE ... LINES option didn't work when used with fixed length rows. (Bug #1704)
Change INSERT DELAYED ... SELECT... to INSERT .... SELECT (Bug #1983)
Safety fix for service 'mysql start' (Bug #1815)
Fixed compiler warnings (a lot of hidden variables detected by the Forte compiler)
Added a lot of 'version_xxx' strings to 'show variables'
Prevent copying of TMP_TABLE_PARAM (This caused core dump bug on Solaris)
Fixed problem with printing sub selects to debug log
We treat Item_param whose value is not set as non-const.
This allows us to avoid use of Item_param's value (not yet existing) in
those fix_fields and fix_length_and_dec that do calculations if their
Items arguments are const. So we can call fix_fields for such items from
mysql_prepare safely.
The right way to fix this is to change the Field::store(longlong) method to be
Field::store(longlong, bool unsigned_flag), but this is better to do in 4.1 than in 4.0
New multi-key-cache handling. This was needed becasue the old one didn't work reliable with MERGE tables.
ALTER TABLE table_name ... CHARACTER SET ... now changes all char/varchar/text columns to the given character set
(One must use ALTER TABLE ... DEFAULT CHARACTER SET ... to change the default character set)
Fixed that have_compress is detected properly (fixes problems with func_compress.test on platforms without zlib)
New syntax for CACHE INDEX ('keys' is optional if no index name is given and one mentions the key cache name only ones)
Removed compiler warnings
Added mysql_set_server_option() to allow clients like PHP to easaily set/reset the multi-statement flag.
Cleaned up (and disabled part of) date/time/datetime format patch. One can't anymore change default read/write date/time/formats.
This is becasue the non standard datetime formats can't be compared as strings and MySQL does still a lot of datetime comparisons as strings
Changed flag argument to str_to_TIME() and get_date() from bool to uint
Removed THD from str_to_xxxx functions and Item class.
Fixed core dump when doing --print-defaults
Move some common string functions to strfunc.cc
Dates as strings are now of type my_charset_bin instead of default_charset()
Introduce IDENT_QUOTED to not have to create an extra copy of simple identifiers (all chars < 128)
Removed xxx_FORMAT_TYPE enums and replaced them with the old TIMESTAMP_xxx enums
Renamed some TIMESTAMP_xxx enums to more appropriate names
Use defines instead of integers for date/time/datetime string lengths
Added to build system and use the new my_strtoll10() function.
