Presence of a subquery in the ON expression of a join
should not block merging the view that contains this join.
Before this patch the such views were converted into
into temporary table views.
this key does not stop" (5.1 version).
UPDATE statement which WHERE clause used key and which invoked trigger
that modified field in this key worked indefinetely.
This problem occured because in cases when UPDATE statement was
executed in update-on-the-fly mode (in which row is updated right
during evaluation of select for WHERE clause) the new version of
the row became visible to select representing WHERE clause and was
updated again and again.
We already solve this problem for UPDATE statements which does not
invoke triggers by detecting the fact that we are going to update
field in key used for scanning and performing update in two steps,
during the first step we gather information about the rows to be
updated and then doing actual updates. We also do this for
MULTI-UPDATE and in its case we even detect situation when such
fields are updated in triggers (actually we simply assume that
we always update fields used in key if we have before update
trigger).
The fix simply extends this check which is done with help of
check_if_key_used()/QUICK_SELECT_I::check_if_keys_used()
routine/method in such way that it also detects cases when
field used in key is updated in trigger. We do this by
changing check_if_key_used() to take field bitmap instead
field list as argument and passing TABLE::write_set
to it (we also have to add info about fields used in
triggers to this bitmap a bit earlier).
As nice side-effect we have more precise and thus more optimal
perfomance-wise check for the MULTI-UPDATE.
Also check_if_key_used() routine and similar method were renamed
to is_key_used()/is_keys_used() in order to better reflect that
it is simple boolean predicate.
Finally, partition_key_modified() routine now also takes field
bitmap instead of field list as argument.
In practice this means that handlerton is now created by the server and is passed to the engine. Plugin startups can now also control how plugins are inited (and can optionally pass values). Bit more flexibility to those who want to write plugin interfaces to the database.
The problem was that if after FLUSH TABLES WITH READ LOCK the user
issued DROP/ALTER PROCEDURE/FUNCTION the operation would fail (as
expected), but after UNLOCK TABLE any attempt to execute the same
operation would lead to the error 1305 "PROCEDURE/FUNCTION does not
exist", and an attempt to execute any stored function will also fail.
This happened because under FLUSH TABLES WITH READ LOCK we couldn't open
and lock mysql.proc table for update, and this fact was erroneously
remembered by setting mysql_proc_table_exists to false, so subsequent
statements believed that mysql.proc doesn't exist, and thus that there
are no functions and procedures in the database.
As a solution, we remove mysql_proc_table_exists flag completely. The
reason is that this optimization didn't work most of the time anyway.
Even if open of mysql.proc failed for some reason when we were trying to
call a function or a procedure, we were setting mysql_proc_table_exists
back to true to force table reopen for the sake of producing the same
error message (the open can fail for number of reasons). The solution
could have been to remember the reason why open failed, but that's a lot
of code for optimization of a rare case. Hence we simply remove this
optimization.
1003: Incorrect table name
in multi-table DELETE the set of tables to delete from actually
references then tables in the other list, e.g:
DELETE alias_of_t1 FROM t1 alias_of_t1 WHERE ....
is a valid statement.
So we must turn off table name syntactical validity check for alias_of_t1
because it's not a table name (even if it looks like one).
In order to do that we add a special flag (TL_OPTION_ALIAS) to
disable the name checking for the aliases in multi-table DELETE.
User name (host name) has limit on length. The server code relies on these
limits when storing the names. The problem was that sometimes these limits
were not checked properly, so that could lead to buffer overflow.
The fix is to check length of user/host name in parser and if string is too
long, throw an error.
There is an existing macros for initializing LEX_STRINGs
with constant strings -> C_STRING_WITH_LEN. Change existing code to use it.
(char *) STRING_WITH_LEN -> C_STRING_WITH_LEN
SELECT right instead of INSERT right was required for an insert into to a view.
This wrong behaviour appeared after the fix for bug #20989. Its intention was
to ask only SELECT right for all tables except the very first for a complex
INSERT query. But that patch has done it in a wrong way and lead to asking
a wrong access right for an insert into a view.
The setup_tables_and_check_access() function now accepts two want_access
parameters. One will be used for the first table and the second for other
tables.
