for bug#16425: Events: no DEFINER clause. The problem was that there
were two rules
ALTER view_algorithm_opt definer ... VIEW ...
ALTER definer EVENT ...
so when there was 'ALTER definer' in the input it was unclear if empty
view_algorithm_opt should be executed or not.
We solve this by introducing three distinct rules
ALTER view_algorithm definer ... VIEW ...
ALTER definer ... VIEW ...
ALTER definer EVENT ...
that remove the ambiguity.
The problem was that some facilities (like CONVERT_TZ() function or
server HELP statement) may require implicit access to some tables in
'mysql' database. This access was done by ordinary means of adding
such tables to the list of tables the query is going to open.
However, if we issued LOCK TABLES before that, we would get "table
was not locked" error trying to open such implicit tables.
The solution is to treat certain tables as MySQL system tables, like
we already do for mysql.proc. Such tables may be opened for reading
at any moment regardless of any locks in effect. The cost of this is
that system table may be locked for writing only together with other
system tables, it is disallowed to lock system tables for writing and
have any other lock on any other table.
After this patch the following tables are treated as MySQL system
tables:
mysql.help_category
mysql.help_keyword
mysql.help_relation
mysql.help_topic
mysql.proc (it already was)
mysql.time_zone
mysql.time_zone_leap_second
mysql.time_zone_name
mysql.time_zone_transition
mysql.time_zone_transition_type
These tables are now opened with open_system_tables_for_read() and
closed with close_system_tables(), or one table may be opened with
open_system_table_for_update() and closed with close_thread_tables()
(the latter is used for mysql.proc table, which is updated as part of
normal MySQL server operation). These functions may be used when
some tables were opened and locked already.
NOTE: online update of time zone tables is not possible during
replication, because there's no time zone cache flush neither on LOCK
TABLES, nor on FLUSH TABLES, so the master may serve stale time zone
data from cache, while on slave updated data will be loaded from the
time zone tables.
construct references invalid name.
Derived tables currently cannot use outer references.
Thus there is no outer context for them.
The 4.1 code takes this fact into account while the
Item_field::fix_outer_field code of 5.0 lost the check that blocks
any attempts to resolve names in outer context for derived tables.
- Fix error message to say that "mysql_upgrade" should be run when
a particular error message is found to be missing
- Dont's set default value on blob's - it will not be used anyway.
result.
For built-in functions like sqrt() function names are hard-coded and can be
compared by pointer. But this isn't the case for a used-defined stored
functions - names there are dynamical and should be compared as strings.
Now the Item_func::eq() function employs my_strcasecmp() function to compare
used-defined stored functions names.
away.
During optimization stage the WHERE conditions can be changed or even
be removed at all if they know for sure to be true of false. Thus they aren't
showed in the EXPLAIN EXTENDED which prints conditions after optimization.
Now if all elements of an Item_cond were removed this Item_cond is substituted
for an Item_int with the int value of the Item_cond.
If there were conditions that were totally optimized away then values of the
saved cond_value and having_value will be printed instead.
During statement prepare phase the tables were locked as if the
statement is being executed, however this is not necessary.
The solution is to not lock tables on statement prepare phase.
Opening tables is enough to prevent DDL on them, and during statement
prepare we do not access nor modify any data.
DATE/DATETIME values are out of the currently supported
4 basic value types (INT,STRING,REAL and DECIMAL).
So expressions (not fields) of compile type DATE/DATETIME are
generally considered as STRING values. This is not so
when they are compared : then they are compared as
INTEGER values.
But the rule for comparison as INTEGERS must be checked
explicitly each time when a comparison is to be performed.
filesort is one such place. However there the check was
not done and hence the expressions (not fields) of type
DATE/DATETIME were sorted by their string representation.
Fixed to compare them as INTEGER values for filesort.
