When checking if an IN predicate can be evaluated using a key
the optimizer makes sure that all the arguments of IN are of
the same result type. To assure that it check whether
Item_func_in::array is filled in.
However Item_func_in::array is set if the types are
the same AND all the arguments are compile time constants.
Fixed by introducing Item_func_in::arg_types_compatible
flag to allow correct checking of the desired condition.
1)
BUG#25507 "multi-row insert delayed + auto increment causes
duplicate key entries on slave" (two concurrrent connections doing
multi-row INSERT DELAYED to insert into an auto_increment column,
caused replication slave to stop with "duplicate key error" (and
binlog was wrong), and BUG#26116 "If multi-row INSERT
DELAYED has errors, statement-based binlogging breaks" (the binlog
was not accounting for all rows inserted, or slave could stop).
The fix is that: in statement-based binlogging, a multi-row INSERT
DELAYED is silently converted to a non-delayed INSERT.
This is supposed to not affect many 5.1 users as in 5.1, the default
binlog format is "mixed", which does not have the bug (the bug is
only with binlog_format=STATEMENT).
We should document how the system delayed_insert thread decides of
its binlog format (which is not modified by this patch):
this decision is taken when the thread is created
and holds until it is terminated (is not affected by any later change
via SET GLOBAL BINLOG_FORMAT). It is also not affected by the binlog
format of the connection which issues INSERT DELAYED (this binlog
format does not affect how the row will be binlogged).
If one wants to change the binlog format of its server with SET
GLOBAL BINLOG_FORMAT, it should do FLUSH TABLES to be sure all
delayed_insert threads terminate and thus new threads are created,
taking into account the new format.
2)
BUG#24432
"INSERT... ON DUPLICATE KEY UPDATE skips auto_increment values".
When in an INSERT ON DUPLICATE KEY UPDATE, using
an autoincrement column, we inserted some autogenerated values and
also updated some rows, some autogenerated values were not used
(for example, even if 10 was the largest autoinc value in the table
at the start of the statement, 12 could be the first autogenerated
value inserted by the statement, instead of 11). One autogenerated
value was lost per updated row. Led to exhausting the range of the
autoincrement column faster.
Bug introduced by fix of BUG#20188; present since 5.0.24 and 5.1.12.
This bug breaks replication from a pre-5.0.24/pre-5.1.12 master.
But the present bugfix, as it makes INSERT ON DUP KEY UPDATE
behave like pre-5.0.24/pre-5.1.12, breaks replication from a
[5.0.24,5.0.34]/[5.1.12,5.1.15]
master to a fixed (5.0.36/5.1.16) slave! To warn users against this when
they upgrade their slave, as agreed with the support team, we add
code for a fixed slave to detect that it is connected to a buggy
master in a situation (INSERT ON DUP KEY UPDATE into autoinc column)
likely to break replication, in which case it cannot replicate so
stops and prints a message to the slave's error log and to SHOW SLAVE
STATUS.
For 5.0.36->[5.0.24,5.0.34] replication or 5.1.16->[5.1.12,5.1.15]
replication we cannot warn as master
does not know the slave's version (but we always recommended to users
to have slave at least as new as master).
As agreed with support, I have asked for an alert to be put into
the MySQL Network Monitoring and Advisory Service.
3) note that I'll re-enable rpl_insert_id as soon as 5.1-rpl gets
the changes from the main 5.1.
duplicate key entries on slave" (two concurrrent connections doing
multi-row INSERT DELAYED to insert into an auto_increment column,
caused replication slave to stop with "duplicate key error" (and
binlog was wrong)), and BUG#26116 "If multi-row INSERT
DELAYED has errors, statement-based binlogging breaks" (the binlog
was not accounting for all rows inserted, or slave could stop).
The fix is that: if (statement-based) binlogging is on, a multi-row
INSERT DELAYED is silently converted to a non-delayed INSERT.
Note: it is not possible to test BUG#25507 in 5.0 (requires mysqlslap),
so it is tested only in the changeset for 5.1. However, BUG#26116
is tested here, and the fix for BUG#25507 is the same code change.
were evaluated.
According to the new rules for string comparison partial indexes on text
columns can be used in the same cases when partial indexes on varchar
columns can be used.
- Implement --secure-file-priv=<dir> option that limits
"load_file", "LOAD DATA" and "SELECT .. INTO OUTFILE" to work
with files in specified dir.
- Use above option for mysqld in mysql-test-run.pl
operations)
Before this change, the boolean predicates:
- X IS TRUE,
- X IS NOT TRUE,
- X IS FALSE,
- X IS NOT FALSE
were implemented by expanding the Item tree in the parser, by using a
construct like:
Item_func_if(Item_func_ifnull(X, <value>), <value>, <value>)
Each <value> was a constant integer, either 0 or 1.
A bug in the implementation of the function IF(a, b, c), in
Item_func_if::fix_length_and_dec(), would cause the following :
When the arguments b and c are both unsigned, the result type of the
function was signed, instead of unsigned.
When the result of the if function is signed, space for the sign could be
counted twice (in the max() expression for a signed argument, and in the
total), causing the member max_length to be too high.
An effect of this is that the final type of IF(x, int(1), int(1)) would be
int(2) instead of int(1).
With this fix, the problems found in Item_func_if::fix_length_and_dec()
have been fixed.
While it's semantically correct to represent 'X IS TRUE' with
Item_func_if(Item_func_ifnull(X, <value>), <value>, <value>),
there are however more problems with this construct.
a)
Building the parse tree involves :
- creating 5 Item instances (3 ints, 1 ifnull, 1 if),
- creating each Item calls my_pthread_getspecific_ptr() once in the operator
new(size), and a second time in the Item::Item() constructor, resulting
in a total of 10 calls to get the current thread.
Evaluating the expression involves evaluating up to 4 nodes at runtime.
This representation could be greatly simplified and improved.
b)
Transforming the parse tree internally with if(ifnull(...)) is fine as long
as this transformation is internal to the server implementation.
With views however, the result of the parse tree is later exposed by the
::print() functions, and stored as part of the view definition.
Doing this has long term consequences:
1)
The original semantic 'X IS TRUE' is lost, and replaced by the
if(ifnull(...)) expression. As a result, SHOW CREATE VIEW does not restore
the original code.
2)
Should a future version of MySQL implement the SQL BOOLEAN data type for
example, views created today using 'X IS NULL' can be exported using
mysqldump, and imported again. Such views would be converted correctly and
automatically to use a BOOLEAN column in the future version.
With 'X IS TRUE' and the current implementations, views using these
"boolean" predicates would not be converted during the export/import, and
would use integer columns instead.
The difference traces back to how SHOW CREATE VIEW preserves 'X IS NULL' but
does not preserve the 'X IS TRUE' semantic.
With this fix, internal representation of 'X IS TRUE' booleans predicates
has changed, so that:
- dedicated Item classes are created for each predicate,
- only 1 Item is created to represent 1 predicate
- my_pthread_getspecific_ptr() is invoked 1 time instead of 10
- SHOW CREATE VIEW preserves the original semantic, and prints 'X IS TRUE'.
Note that, because of the fix in Item_func_if, views created before this fix
will:
- correctly use a int(1) type instead of int(2) for boolean predicates,
- incorrectly print the if(ifnull(...), ...) expression in SHOW CREATE VIEW,
since the original semantic (X IS TRUE) has been lost.
- except for the syntax used in SHOW CREATE VIEW, these views will operate
properly, no action is needed.
Views created after this fix will operate correctly, and will preserve the
original code semantic in SHOW CREATE VIEW.
