- Starting time of a query sent by bootstrapping wasn't initialized
and starting time defaulted to 0. This later used value by NOW-
item and was translated to 1970-01-01 11:00:00.
- Marketing the time with thd->set_time() before the call to
mysql_parse resolves this issue.
- set_time was refactored to be part of the thd->init_for_queries-
process.
Several problems fixed:
1. There was a "catch-all" context initialization in setup_tables()
that was causing the table that we insert into to be visible in the
SELECT part of an INSERT .. SELECT .. statement with no tables in
its FROM clause. This was making sure all the under-initialized
contexts in various parts of the code are not left uninitialized.
Fixed by removing the "catch-all" statement and initializing the
context in the parser.
2. Incomplete name resolution context when resolving the right-hand
values in the ON DUPLICATE KEY UPDATE ... part of an INSERT ... SELECT ...
caused columns from NATURAL JOIN/JOIN USING table references in the
FROM clause of the select to be unavailable.
Fixed by establishing a proper name resolution context.
3. When setting up the special name resolution context for problem 2
there was no check for cases where an aggregate function without a
GROUP BY effectively takes the column from the SELECT part of an
INSERT ... SELECT unavailable for ON DUPLICATE KEY UPDATE.
Fixed by checking for that condition when setting up the name
resolution context.
The problem happened because those tests were using "cp932" and "ucs2" without checking whether these character sets are available. This fix moves test parts to make character set specific parts be tested only if they are:
- some parts were moved to "ctype_ucs.test" and "ctype_cp932.test"
- some parts were moved to the newly added tests "innodb-ucs2.test", "mysqlbinglog-cp932.test" and "sp-ucs2.test"
- Starting time of a query sent by file bootstrapping wasn't initialized
and starting time defaulted to 0. This later used value by the Now-
item and is translated to 1970-01-01 11:00:00.
- marking the time with thd->set_time() before the call to
mysql_parse resolves this issue.
UPDATE contains wrong data if the SELECT employs a temporary table.
If the UPDATE values of the INSERT .. SELECT .. ON DUPLICATE KEY UPDATE
statement contains fields from the SELECT part and the select employs a
temporary table then those fields will contain wrong values because they
aren't corrected to get data from the temporary table.
The solution is to add these fields to the selects all_fields list,
to store pointers to those fields in the selects ref_pointer_array and
to access them via Item_ref objects.
The substitution for Item_ref objects is done in the new function called
Item_field::update_value_transformer(). It is called through the
item->transform() mechanism at the end of the select_insert::prepare()
function.
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.
ENUMs weren't allowed to have character 0xff, a perfectly good character in some locales.
This was circumvented by mapping 0xff in ENUMs to ',', thereby prevent actual commas from
being used. Now if 0xff makes an appearance, we find a character not used in the enum and
use that as a separator. If no such character exists, we throw an error.
Any solution would have broken some sort of existing behaviour. This solution should
serve both fractions (those with 0xff and those with ',' in their enums), but
WILL REQUIRE A DUMP/RESTORE CYCLE FROM THOSE WITH 0xff IN THEIR ENUMS. :-/
That is, mysqldump with their current server, and restore when upgrading to one with
this patch.
