The parser returned a syntax error message for the queries with join
expressions like this t1 JOIN t2 [LEFT | RIGHT] JOIN t3 ON ... ON ... when
the second operand of the outer JOIN operation with ON clause was another
join expression with ON clause. In this expression the JOIN operator is
right-associative, i.e. expression has to be parsed as the expression
t1 JOIN (t2 [LEFT | RIGHT] JOIN t3 ON ... ) ON ...
Such join expressions are hard to parse because the outer JOIN is
left-associative if there is no ON clause for the first outer JOIN operator.
The patch implements the solution when the JOIN operator is always parsed
as right-associative and builds first the right-associative tree. If it
happens that there is no corresponding ON clause for this operator the
tree is converted to left-associative.
The idea of the solution was taken from the patch by Martin Hansson
"WL#8083: Fixed the join_table rule" from MySQL-8.0 code line.
As the grammar rules related to join expressions in MySQL-8.0 and
MariaDB-5.5+ are quite different MariaDB solution could not borrow
any code from the MySQL-8.0 solution.
and WHERE filter afterwards
This patch complements the patch fixing the bug MDEV-6892. The latter
properly handled queries that used mergeable views returning constant
columns as inner tables of outer joins and whose where clause contained
predicates referring to these columns if the predicates of happened not
to be equality predicates. Otherwise the server still could return wrong
result sets for such queries. Besides the fix for MDEV-6892 prevented
some possible conversions of outer joins to inner joins for such queries.
This patch corrected the function check_simple_equality() to handle
properly conjunctive equalities of the where clause that refer to the
constant columns of mergeable views used as inner tables of an outer join.
The patch also changed the code of Item_direct_view_ref::not_null_tables().
This change allowed to take into account predicates containing references
to constant columns of mergeable views when converting outer joins into
inner joins.
in where clause
The classes Item_func_isnottrue and Item_func_isnotfalse inherited the
implementation of the eval_not_null_tables method from the Item_func
class. As a result the not_null_tables_cache was set incorrectly for
the objects of these classes. It led to improper conversion of outer
joins to inner joins when the where clause of the processed query
contained IS NOT TRUE or IS NOT FALSE predicates. The coverted query
in many cases produced a wrong result set.
Handling of top level conjuncts in WHERE whose used_tables() contained
RAND_TABLE_BIT in the function make_join_select() was incorrect.
As a result if such a conjunct referred to fields non of which belonged
to the last joined table it was pushed twice. (This could be seen
for a test case from subselect.test whose output was changed after this
patch had been applied. In 10.1 when running EXPLAIN FORMAT=JSON for
the query from this test case we clearly see that one of the conjuncts
is pushed twice.) This fact by itself was not good. Besides, if such a
conjunct was pushed to a table that was the result of materialization
of a semi-join the query could return a wrong result set. In particular
we could watch it for queries with semi-join subqueries whose left parts
used stored functions without "deterministic' specifier.
as well as
MDEV-19500 Update with join stopped worked if there is a call to a procedure in a trigger
MDEV-19521 Update Table Fails with Trigger and Stored Function
MDEV-19497 Replication stops because table not found
MDEV-19527 UPDATE + JOIN + TRIGGERS = table doesn't exists error
Reimplement the fix for (5d510fdbf0)
MDEV-18507 can't update temporary table when joined with table with triggers on read-only
instead of calling open_tables() twice, put multi-update
prepare code inside open_tables() loop.
Add a test for a MDL backoff-and-retry loop inside open_tables()
across multi-update prepare code.
This patch complements the patch that fixes bug MDEV-18479.
This patch takes care of possible overflow when calculating the
estimated number of rows in a materialized derived table / view.
This bug could happen when queries with nested outer joins were
executed employing join buffers. At such an execution if the method
JOIN_CACHE::join_records() is called when a join buffer has become
full no 'first_unmatched' field should be cleaned up in the JOIN_TAB
structure to which the join cache with this buffer is attached.
or server crashes in JOIN::fix_all_splittings_in_plan after EXPLAIN
This patch resolves the problem of overflowing when performing
calculations to estimate the cost of an evaluated query execution plan.
The overflowing in a non-debug build could cause different kind of
problems uncluding crashes of the server.
This patch complements the original patch for MDEV-18896 that prevents
conversions to semi-joins in tableless selects used in INSERT statements
in post-5.5 versions of the server.
The test case was corrected as well to ensure that potential conversion
to jtbm semi-joins is also checked (the problem was that one of
the preceeding testcases in subselect_sj.test did not restore the
state of the optimizer switch leaving the 'materialization' in the state
'off' and so blocking this check).
Noticed an inconsistency in the state of select_lex::table_list used
in INSERT statements and left a comment about this.
Before killing the server, we must issue FLUSH TABLES in order
to cleanly close any MyISAM system tables, to avoid warnings about
them when restarting.
This patch fixes an invalid read in fill_effective_table_privileges
triggered by a grant_version increase between a PREPARE for a
statement creating a view from I_S and EXECUTE.
A tmp table was created and free'd while preparing the statement,
TABLE_LIST::table_name was set to point to the tmp table
TABLE_SHARE::table_name which no longer existed after preparing was
done.
The grant version increase made fill_effective_table_privileges
called during EXECUTE to try fetch the updated grant info and
this is where the dangling table name was used.
triggers are opened and tables used in triggers are prelocked in
open_tables(). But multi-update can detect what tables will actually
be updated only later, after all main tables are opened.
Meaning, if a table is used in multi-update, but is not actually updated,
its on-update treggers will be opened and tables will be prelocked,
even if it's unnecessary. This can cause more tables to be
write-locked than needed, causing read_only errors, privilege errors
and lock waits.
Fix: don't open/prelock triggers unless table->updating is true.
In multi-update after setting table->updating=true, do a second
open_tables() for newly added tables, if any.
it always required UPDATE privilege on views, not being able to detect
when a views was not actually updated in multi-update.
fix: instead of marking all tables as "updating" by default,
only set "updating" on tables that will actually be updated
by multi-update. And mark the view "updating" if any of the
view's tables is.
InnoDB could return the same list again and again if the buffer
passed to trx_recover_for_mysql() is smaller than the number of
transactions that InnoDB recovered in XA PREPARE state.
We introduce the transaction state TRX_PREPARED_RECOVERED, which
is like TRX_PREPARED, but will be set during trx_recover_for_mysql()
so that each transaction will only be returned once.
Because init_server_components() is invoking ha_recover() twice,
we must reset the state of the transactions back to TRX_PREPARED
after returning the complete list, so that repeated traversals
will see the complete list again, instead of seeing an empty list.
Without this tweak, the test main.tc_heuristic_recover would hang
in MariaDB 10.1.
dict_create_foreign_constraints_low(): Tolerate the keywords
IGNORE and ONLINE between the keywords ALTER and TABLE.
We should really remove the hacky FOREIGN KEY constraint parser
from InnoDB.
Always set SERVER_MORE_RESULTS_EXIST when executing stored procedure statements
If statements produce a result, EOF packet needs this flag (SP ends
with an OK packet). IF statetement does not produce a result, affected rows
count are part of the final OK packet.
select from I_S
Problem:
========
When applier thread tries to access 'variable_name' of
INFORMATION_SCHEMA.SESSION_VARIABLES table through triggers, it results in an
abnormal exit of slave server.
Analysis:
========
At the time of replication of stored routines and triggers, their associated
security context will be sent by the master. The applier thread on the slave
server will use this information to set the required security context for the
execution of stored routines and triggers. This is achieved as follows.
->The stored routine object has a member named 'm_security_ctx' which holds the
security context received from master.
->The applier thread's security_ctx is stored into a 'backup' object.
->Set the applier thread's security_ctx to 'm_security_ctx'.
->Upon the completion of stored routine execution restore the original security
context of applier thread from the backup.
During the above process the 'm_security_ctx' object is not initialized
properly. Hence the 'external_user' of 'm_security_ctx' has invalid value for
this variable and accessing this variable results in abnormal exit of server.
Fix:
===
Invoke the Security_context::init() call from the constructor of stored routine
so that 'm_security_ctx' gets initialized properly.
If an IN-subquery is used in a table-less select the current code
should never consider it as candidate for semi-join optimizations.
Yet the function check_and_do_in_subquery_rewrites() improperly
checked the property "to be a table-less select". As a result
such select in IN subquery was used in INSERT .. SELECT then
the IN subquery by mistake was registered as a semi-join subquery
and convert_subq_to_sj() was called for it. However the code of
this function does not assume that the parent select of the subquery
could be a table-less select.
1. Always drop merged_for_insert flag on cleanup (there could be errors which prevent TABLE to be assigned)
2. Make more precise cleanup of select parts which was touched
Disable LOAD DATA LOCAL INFILE suport by default and
auto-enable it for the duration of one query, if the query
string starts with the word "load". In all other cases the application
should enable LOAD DATA LOCAL INFILE support explicitly.
