min() and max() functions are implemented in MySQL as macros.
This means that max(a,b) is expanded to: ((a) > (b) ? (a) : (b))
Note how 'a' is quoted two times.
Now imagine 'a' is a recursive function call that's several 10s of levels deep.
And the recursive function does max() with a function arg as well to dive into
recursion.
This means that simple function call can take most of the clock time.
Identified and fixed several such calls to max()/min() : including the IF()
sql function implementation.
Calling List<Cached_item>::delete_elements for the same list twice
caused a crash of the server in the function JOIN::cleaunup.
Ensured that delete_elements() in JOIN::cleanup would be called only once.
Range scan in descending order for c <= <col> <= c type of
ranges was ignoring the DESC flag.
However some engines like InnoDB have the primary key parts
as a suffix for every secondary key.
When such primary key suffix is used for ordering ignoring
the DESC is not valid.
But we generally would like to do this because it's faster.
Fixed by performing only reverse scan if the primary key is used.
Removed some dead code in the process.
mysqltest disconnect/connect-combo could be so
quick that connect would hit the server before
it had processed the disconnect. Since that
resulted in one more concurrent connection than
we meant to have, global or per-user
max-user-connections could be exceeded.
This could lead to "random" failures in tests
that set those limits.
build)
The crash was caused by freeing the internal parser stack during the parser
execution.
This occured only for complex stored procedures, after reallocating the parser
stack using my_yyoverflow(), with the following C call stack:
- MYSQLparse()
- any rule calling sp_head::restore_lex()
- lex_end()
- x_free(lex->yacc_yyss), xfree(lex->yacc_yyvs)
The root cause is the implementation of stored procedures, which breaks the
assumption from 4.1 that there is only one LEX structure per parser call.
The solution is to separate the LEX structure into:
- attributes that represent a statement (the current LEX structure),
- attributes that relate to the syntax parser itself (Yacc_state),
so that parsing multiple statements in stored programs can create multiple
LEX structures while not changing the unique Yacc_state.
Now, Yacc_state and the existing Lex_input_stream are aggregated into
Parser_state, a structure that represent the complete state of the (Lexical +
Syntax) parser.
and value-list
The server returns unexpected results if a right side of the
NOT IN clause consists of NULL value and some constants of
the same type, for example:
SELECT * FROM t WHERE NOT t.id IN (NULL, 1, 2)
may return 3, 4, 5 etc if a table contains these values.
The Item_func_in::val_int method has been modified:
unnecessary resets of an Item_func_case::has_null field
value has been moved outside of an argument comparison
loop. (Also unnecessary re-initialization of the null_value
field has been moved).
Problem was that ha_partition had HA_FILE_BASED flag set
(since it uses a .par file), but after open it uses the first partitions
flags, which results in different case handling for create and for
open.
Solution was to change the underlying partition name so it was consistent.
(Only happens when lower_case_table_names = 2, i.e. Mac OS X and storage
engines without HA_FILE_BASED, like InnoDB and Memory.)
(Recommit after adding rename of check_lowercase_names to
get_canonical_filename, and moved it from handler.h to mysql_priv.h)
NOTE: if a mixed case name for a partitioned table was created when
lower_case_table_name = 2 it should be renamed or dropped before using
the updated version (See bug#37402 for more info)
Problem 1: tests often fail in pushbuild with a timeout when waiting
for the slave to start/stop/receive error.
Fix 1: Updated the wait_for_slave_* macros in the following way:
- The timeout is increased by a factor ten
- Refactored the macros so that wait_for_slave_param does the work for
the other macros.
Problem 2: Tests are often incorrectly written, lacking a
source include/wait_for_slave_to_[start|stop].inc.
Fix 2: Improved the chance to get it right by adding
include/start_slave.inc and include/stop_slave.inc, and updated tests
to use these.
Problem 3: The the built-in test language command
wait_for_slave_to_stop is a misnomer (does not wait for the slave io
thread) and does not give as much debug info in case of failure as
the otherwise equivalent macro
source include/wait_for_slave_sql_to_stop.inc
Fix 3: Replaced all calls to the built-in command by a call to the
macro.
Problem 4: Some, but not all, of the wait_for_slave_* macros had an
implicit connection slave. This made some tests confusing to read,
and made it more difficult to use the macro in circular replication
scenarios, where the connection named master needs to wait.
Fix 4: Removed the implicit connection slave from all
wait_for_slave_* macros, and updated tests to use an explicit
connection slave where necessary.
Problem 5: The macros wait_slave_status.inc and wait_show_pattern.inc
were unused. Moreover, using them is difficult and error-prone.
Fix 5: remove these macros.
Problem 6: log_bin_trust_function_creators_basic failed when running
tests because it assumed @@global.log_bin_trust_function_creators=1,
and some tests modified this variable without resetting it to its
original value.
Fix 6: All tests that use this variable have been updated so that
they reset the value at end of test.
offset for time part in UUIDs was 1/1000 of what it
should be. In other words, offset was off.
Also handle the case where we count into the future
when several UUIDs are generated in one "tick", and
then the next call is late enough for us to unwind
some but not all of those borrowed ticks.
Lastly, handle the case where we keep borrowing and
borrowing until the tick-counter overflows by also
changing into a new "numberspace" by creating a new
random suffix.
offset for time part in UUIDs was 1/1000 of what it
should be. In other words, offset was off.
Also handle the case where we count into the future
when several UUIDs are generated in one "tick", and
then the next call is late enough for us to unwind
some but not all of those borrowed ticks.
Lastly, handle the case where we keep borrowing and
borrowing until the tick-counter overflows by also
changing into a new "numberspace" by creating a new
random suffix.
The problem is that relying on the output of the 'ls' command is not
portable as its behavior is not the same between systems and it might
even not be available at all in (Windows).
So I added list_files that relies on the portable mysys library instead.
(and also list_files_write_file and list_files_append_file,
since the test was using '--exec ls' in that way.)
enabled)
Before this fix, the lexer and parser would treat the ';' character as a
different token (either ';' or END_OF_INPUT), based on convoluted logic,
which failed in simple cases where a stored procedure is implemented as a
single statement, and used in a multi query.
With this fix:
- the character ';' is always parsed as a ';' token in the lexer,
- parsing multi queries is implemented in the parser, in the 'query:' rules,
- the value of thd->client_capabilities, which is the capabilities
negotiated between the client and the server during bootstrap,
is immutable and not arbitrarily modified during parsing (which was the
root cause of the bug)
When there is an error executing EXISTS predicates they return NULL as their string
or decimal value but don't set the NULL value flag.
Fixed by returning 0 (as a decimal or a string) on error exectuting the subquery.
Note that we can't return NULL as EXISTS is not supposed to return NULL.
Problem 1: main.loaddata tried to trigger an error caused by
reading files outside the vardir, by reading itself. However,
if loaddata.test is not world-readable (e.g., umask=0077),
then another error is triggered.
Fix 1: allow the other error too.
Problem 2: rpl_slave_skip and rpl_innodb_mixed_dml tried to
copy a file from mysql-test/suite/rpl/data to mysql-test/var
and then read it. That failed too if umask=0077, since the
file would not become world-readable.
Fix 2: move the files from mysql-test/suite/rpl/data to
mysql-test/std_data and update tests accordingly. Remove
the directory mysql-test/suite/rpl/data.
