A REPLACE in the MERGE engine is actually a REPLACE
into one (FIRST or LAST) of the underlying MyISAM
tables. So in effect the server works on the meta
data of the MERGE table, while the real insert happens
in the MyISAM table.
The MERGE table has no index, while MyISAM has a
unique index. When a REPLACE into a MERGE table (
and the REPLACE conflicts with a duplicate in a
child table) is done, we try to access the duplicate
key information for the MERGE table. This information
actually does not exist, hence this results in a crash.
The problem can be resolved by modifying the MERGE
engine to provide us the duplicate key information
directly, instead of just returning the MyISAM index
number as the error key. Then the SQL layer (or "the
server") does not try to access the key_info of the
MERGE table, which does not exist.
The current patch modifies the MERGE engine to provide
the position for a record where a unique key violation
occurs.
include/myisammrg.h:
Bug#45800 crash when replacing into a merge table and there is a duplicate
Add a member to the st_mymerge_info structure that will
store the duplicate key offset in the MERGE table. This
offset will be the sum of the record offset of the MyISAM
table within the MERGE table and the offset of the record
within the MyISAM table.
mysql-test/r/merge.result:
Bug#45800 crash when replacing into a merge table and there is a duplicate
Result file for the test case.
mysql-test/t/merge.test:
Bug#45800 crash when replacing into a merge table and there is a duplicate
Added test case for both REPLACE and INSERT...ON DUPLICATE UPDATE.
storage/myisammrg/ha_myisammrg.cc:
Bug#45800 crash when replacing into a merge table and there is a duplicate
The info method now will process the HA_STATUS_ERRKEY flag
and will return the index and the offset of the duplicate
key.
storage/myisammrg/ha_myisammrg.h:
Bug#45800 crash when replacing into a merge table and there is a duplicate
Set the HA_DUPLICATE_POS flag to indicate that the duplicate
key information is now available in the MERGE storage engine.
storage/myisammrg/myrg_info.c:
Bug#45800 crash when replacing into a merge table and there is a duplicate
We modify the myrg_status function to return the position of the
duplicate key. The duplicate key position in the MERGE table will
be the MyISAM file_offset and the offset within the MyISAM table
of the start position of the records.
A REPLACE in the MERGE engine is actually a REPLACE
into one (FIRST or LAST) of the underlying MyISAM
tables. So in effect the server works on the meta
data of the MERGE table, while the real insert happens
in the MyISAM table.
The MERGE table has no index, while MyISAM has a
unique index. When a REPLACE into a MERGE table (
and the REPLACE conflicts with a duplicate in a
child table) is done, we try to access the duplicate
key information for the MERGE table. This information
actually does not exist, hence this results in a crash.
The problem can be resolved by modifying the MERGE
engine to provide us the duplicate key information
directly, instead of just returning the MyISAM index
number as the error key. Then the SQL layer (or "the
server") does not try to access the key_info of the
MERGE table, which does not exist.
The current patch modifies the MERGE engine to provide
the position for a record where a unique key violation
occurs.
and base tables
myrg_attach_children() could reuse a buffer that was allocated
previously based on a definition of a child table. The problem
was that the child's definition might have been changed, so
reusing the buffer could lead to crashes or valgrind errors
under some circumstances.
Fixed by changing myrg_attach_children() so that the
rec_per_key_part buffer is reused only when the child table
have not changed, and reallocated otherwise (the old buffer is
deallocated if necessary).
include/myisammrg.h:
Added a pointer to need_compat_check as an argument to
myrg_attach_children().
mysql-test/r/merge.result:
Added a test case for bug #45796.
mysql-test/t/merge.test:
Added a test case for bug #45796.
storage/myisammrg/ha_myisammrg.cc:
Pass a pointer to need_compat_check to myrg_attach_children().
storage/myisammrg/myrg_open.c:
Changed myrg_attach_children() so that the
rec_per_key_part buffer is reused only when the child table
have not changed, and reallocated otherwise (the old buffer
is deallocated if necessary).
and base tables
myrg_attach_children() could reuse a buffer that was allocated
previously based on a definition of a child table. The problem
was that the child's definition might have been changed, so
reusing the buffer could lead to crashes or valgrind errors
under some circumstances.
Fixed by changing myrg_attach_children() so that the
rec_per_key_part buffer is reused only when the child table
have not changed, and reallocated otherwise (the old buffer is
deallocated if necessary).
Remove custom DLL loader code from innodb plugin code, use
symbols exported from mysqld.
storage/innodb_plugin/handler/ha_innodb.cc:
Remove a Win32 workaround for current_thd.
The original problem that innodb plugin used
value of TLS variable across DLL boundaries is
solved in MySQL server (current_thd is a function
not TLS variable now)
storage/innodb_plugin/handler/handler0alter.cc:
Remove custom delay loader
storage/innodb_plugin/handler/handler0vars.h:
Remove custom delay loader
storage/innodb_plugin/handler/i_s.cc:
Remove custom delay loader
storage/innodb_plugin/handler/win_delay_loader.cc:
Remove custom delay loader
storage/innodb_plugin/plug.in:
Remove commented out MYSQL_PLUGIN_STATIC,
CMake would not parse that correctly
mysql-test/r/information_schema.result:
Fixed a result file.
mysql-test/r/innodb-autoinc.result:
Fixed a result file.
mysql-test/t/connect.test:
Fixed a problem with merge, needed to close
connections and use the default
The conformance checker was not taking into
account, and, making concessions for acceptable
incompatibilites in tables created by
versions earlier than 4.1.
The current patch relaxes the conformance
checker to ignore differences in key_alg
and language for tables created by versions
earlier than 4.1.
storage/myisam/ha_myisam.cc:
Modify check_definition to ignore differences
in key_alg and language for tables created
by versions earlier than 4.1.
The conformance checker was not taking into
account, and, making concessions for acceptable
incompatibilites in tables created by
versions earlier than 4.1.
The current patch relaxes the conformance
checker to ignore differences in key_alg
and language for tables created by versions
earlier than 4.1.
Probe definition file is now a separate file that is copied during
build to the correct location, this enforces dependency requirements
correctly and allows builds to work when using the current or separate
build directories
Probe definition file is now a separate file that is copied during
build to the correct location, this enforces dependency requirements
correctly and allows builds to work when using the current or separate
build directories
This problem comes while inserting a duplicate row in merge table
without key but the child table has a primary key.
While forming the error message handler tries to locate the key field
which is creating this problem but as there is no key on the merge
table there is a segmentation fault.
mysql-test/r/merge.result:
Updated results with new test for this bug.
mysql-test/t/merge.test:
Added new test to test error generated from a key on child table
where merge table doesn't have any key.
storage/myisammrg/ha_myisammrg.cc:
Added a new check to see if the value of error key is higher than
the number of key in merge table and if it is the error key set
to MAX_KEY. The error message generation routine treats MAX_KEY as
unknown key and doesn't tries to access this in key_info.
This problem comes while inserting a duplicate row in merge table
without key but the child table has a primary key.
While forming the error message handler tries to locate the key field
which is creating this problem but as there is no key on the merge
table there is a segmentation fault.
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
A Query in the MyISAM merge table was crashing
if the index merge algorithm was being used
Index Merge optimization requires the reading of
multiple indexes at the same time. Reading multiple
indexes at once with current SE API means that we
need to have handler instance for each to-be-read
index. This is done by creating clones of the handlers
instances. The clone internally does a open of the handler.
The open for a MERGE engine is handled in the following
phases
1) open parent table
2) generate list of underlying
table
3) attach underlying tables
But the current implementation does only the first
phase (i.e.) open parent table.
The current patch fixes this at the MERGE engine level,
by handling the clone operation within the MERGE engine
rather than in the storage engine API. It opens and
attaches the MyISAM tables on the MyISAM storage engine
interface directly within the MERGE engine. The new MyISAM
table instances, as well as the MERGE clone itself, are not
visible in the table cache. This is not a problem because
all locking is handled by the original MERGE table from which
this is cloned of.
mysql-test/r/merge.result:
updated the result file to reflect the new tests
added to test the fix
mysql-test/t/merge.test:
Added new tests to verify that the index merge
algorithm does not crash in the merge engine.
storage/myisammrg/ha_myisammrg.cc:
Implement the clone method, that handles
1) Cloning the handler
2) Opening underlying MYISAM child tables
3) Copies the state of the original handler and the children
into the cloned instances
4) Sets the appropriate flags
storage/myisammrg/ha_myisammrg.h:
Added a flag that is set to indicate that the current
instance is cloned. Also added the prototype or the clone
method.
storage/myisammrg/myrg_open.c:
Since we do now again use myrg_open() in the server
removed the comments marking this as deadcode.
A Query in the MyISAM merge table was crashing
if the index merge algorithm was being used
Index Merge optimization requires the reading of
multiple indexes at the same time. Reading multiple
indexes at once with current SE API means that we
need to have handler instance for each to-be-read
index. This is done by creating clones of the handlers
instances. The clone internally does a open of the handler.
The open for a MERGE engine is handled in the following
phases
1) open parent table
2) generate list of underlying
table
3) attach underlying tables
But the current implementation does only the first
phase (i.e.) open parent table.
The current patch fixes this at the MERGE engine level,
by handling the clone operation within the MERGE engine
rather than in the storage engine API. It opens and
attaches the MyISAM tables on the MyISAM storage engine
interface directly within the MERGE engine. The new MyISAM
table instances, as well as the MERGE clone itself, are not
visible in the table cache. This is not a problem because
all locking is handled by the original MERGE table from which
this is cloned of.
Every subsequent query to a merge table with indexes was lowering
down cardinality.
The problem was that key statistics was not cleared when merge
children were detached. Causing next attach children perform
incremental key statistics calculation.
Fixed by clearing key statistics when attaching first child.
mysql-test/r/merge.result:
A test case for BUG#39185.
mysql-test/t/merge.test:
A test case for BUG#39185.
storage/myisammrg/myrg_open.c:
Clear key statistics when we're attaching first child, even
if it's buffer was allocated before. This is needed because
detach_children() doesn't clear statistics, causing incremental
statistics calculation.
