PROBLEM: After WL 4144, when using MyISAM Merge tables, the routine
open_and_lock_tables will append to the list of tables to lock, the
base tables that make up the MERGE table. This has two side-effects in
replication:
1. On the master side, we log additional table maps for the base
tables, since they appear in the list of locked tables, even
though we don't really use them at the slave.
2. On the slave side, when opening a MERGE table while applying a
ROW event, additional tables are appended to the list of tables
to lock.
Side-effect #1 is not harmful. It's just that when using MyISAM Merge
tables a few table maps more may be logged.
Side-effect #2, is harmful, because the list rli->tables_to_lock is an
extended structure from TABLE_LIST in which the extra fields are
filled from the table maps that are processed. Since
open_and_lock_tables appends tables to the list after all table map
events have been processed we end up with entries without
replication/table map data on them. Thus when trying to access that
info for these extra tables, the server will crash.
SOLUTION: We fix side-effect #2 by making sure that we access the
replication part of the structure for those in the list that were
accounted for when processing the correspondent table map events. All
in all, we never go beyond rli->tables_to_lock_count.
We also deploy an assertion when clearing rli->tables_to_lock, making
sure that the base tables are not in the list anymore (were closed in
close_thread_tables).
CHECK_SIMPLE_EQUALITY
PROBLEM:
Crash in "check_simple_equality" when using a subquery with "IN" and
"ALL" in prepare.
ANALYSIS:
Crash can be reproduced using a simplified query like this one:
prepare s from "select 1 from g1 where 1 < all (
select @:=(1 in (select 1 from g1)) from g1)";
This bug is currently present only on 5.5.and 5.1. Its fixed as part
of work log(#1110) in 5.6. We are taking one change to fix this
in 5.5 and 5.1.
Problem seems to be present because we are trying to evaluate "is_null"
on an argument which is part of a subquery
(In Item_is_not_null_test::update_used_tables()).
But the condition to evaluate is only when we do not have a sub query
present, which means to say that "with_subselect" is not set.
With respect to the above query, we create an object of type
"Item_in_optimizer" which by definition is always associated with a
subquery. While in 5.6 we set "with_subselect" to true for
"Item_in_optimizer" object, we do not do the same in 5.5. This results in
the evaluation for "is_null" resulting in a coredump.
So, we are now setting "with_subselect" to true for "Item_in_optimizer"
in 5.1 and 5.5.
PARTITION STATISTICS
Problem was the fix for bug#11756867; It always used the first
partitions, and stopped after it checked 10 [sub]partitions.
(or until it found a partition which would contain a match).
This results in bad statistics for tables where the first 10 partitions
don't represent the majority of the data (like when the first 10
partitions only contained a few rows in total).
The solution was to take statisics from the partitions containing
the most rows instead:
Added an array of partition ids which is sorted by number of records
in descending order.
this array is used in records_in_range to cover as many records as
possible in as few calls as possible.
Also changed the limit of how many partitions to use for the statistics
from a static max of 10 partitions, into a dynamic model:
Maximum number of partitions is now log2(total number of partitions)
taken from the ordered array.
It will continue calling partitions records_in_range until it has
checked:
(total rows in matching partitions) * (maximum number of partitions)
/ (number of used partitions)
Also reverted the changes for ha_partition::scan_time() and
ha_partition::estimate_rows_upper_bound() to before
the fix of bug#11756867. Since they are not as slow as
records_in_range.
Suppress innodb_bug34300 from failing if InnoDB prints:
120221 11:05:03 InnoDB: ERROR: the age of the last checkpoint is 9439048,
InnoDB: which exceeds the log group capacity 9433498.
by default the log capacity is 2 log files, 5 MB each.
RESULT FROM PREVIOUS TRANSACTION
The current Query Cache API is not fully compatible with
the partitioning engine.
There is no good way to implement support for QC due to:
1) a static callback for ha_partition would need to have access
to all partition names and call the underlying callback for each
[sub]partition with the correct name.
2) pruning would be impossible, even if one used the ulonglong
engine_data due to if engine_data is changed, the table is
invalidated by the QC.
So the only viable solution to avoid incorrect data is to not allow
caching of queries using partitioned tables.
(There are some extra changes, due to removal of \r as line break)
This bug was originally filed and fixed as Bug#12612184. The original
fix was buggy, and it was patched by Bug#12704861. Also that patch was
buggy (potentially breaking crash recovery), and both fixes were
reverted.
This fix was not ported to the built-in InnoDB of MySQL 5.1, because
the function signatures of many core functions are different from
InnoDB Plugin and later versions. The block allocation routines and
their callers would have to changed so that they handle block
descriptors instead of page frames.
When a record is updated so that its size grows, non-updated columns
can be selected for external (off-page) storage. The bug is that the
initially inserted updated record contains an all-zero BLOB pointer to
the field that was not updated. Only after the BLOB pages have been
allocated and written, the valid pointer can be written to the record.
Between the release of the page latch in mtr_commit(mtr) after
btr_cur_pessimistic_update() and the re-latching of the page in
btr_pcur_restore_position(), other threads can see the invalid BLOB
pointer consisting of 20 zero bytes. Moreover, if the system crashes
at this point, the situation could persist after crash recovery, and
the contents of the non-updated column would be permanently lost.
The problem is amplified by the ROW_FORMAT=DYNAMIC and
ROW_FORMAT=COMPRESSED that were introduced in
innodb_file_format=barracuda in InnoDB Plugin, but the bug does exist
in all InnoDB versions.
The fix is as follows. After a pessimistic B-tree operation that needs
to write out off-page columns, allocate the pages for these columns in
the mini-transaction that performed the B-tree operation (btr_mtr),
but write the pages in a separate mini-transaction (blob_mtr). Do
mtr_commit(blob_mtr) before mtr_commit(btr_mtr). A quirk: Do not reuse
pages that were previously freed in btr_mtr. Only write the off-page
columns to 'fresh' pages.
In this way, crash recovery will see redo log entries for blob_mtr
before any redo log entry for btr_mtr. It will apply the BLOB page
writes to pages that were marked free at that point. If crash recovery
fails to see all of the btr_mtr redo log, there will be some
unreachable BLOB data in free pages, but the B-tree will be in a
consistent state.
btr_page_alloc_low(): Renamed from btr_page_alloc(). Add the parameter
init_mtr. Return an allocated block, or NULL. If init_mtr!=mtr but
the page was already X-latched in mtr, do not initialize the page.
btr_page_alloc(): Wrapper for btr_page_alloc_for_ibuf() and
btr_page_alloc_low().
btr_page_free(): Add a debug assertion that the page was a B-tree page.
btr_lift_page_up(): Return the father block.
btr_compress(), btr_cur_compress_if_useful(): Add the parameter ibool
adjust, for adjusting the cursor position.
btr_cur_pessimistic_update(): Preserve the cursor position when
big_rec will be written and the new flag BTR_KEEP_POS_FLAG is defined.
Remove a duplicate rec_get_offsets() call. Keep the X-latch on
index->lock when big_rec is needed.
btr_store_big_rec_extern_fields(): Replace update_inplace with
an operation code, and local_mtr with btr_mtr. When not doing a
fresh insert and btr_mtr has freed pages, put aside any pages that
were previously X-latched in btr_mtr, and free the pages after
writing out all data. The data must be written to 'fresh' pages,
because btr_mtr will be committed and written to the redo log after
the BLOB writes have been written to the redo log.
btr_blob_op_is_update(): Check if an operation passed to
btr_store_big_rec_extern_fields() is an update or insert-by-update.
fseg_alloc_free_page_low(), fsp_alloc_free_page(),
fseg_alloc_free_extent(), fseg_alloc_free_page_general(): Add the
parameter init_mtr. Return an allocated block, or NULL. If
init_mtr!=mtr but the page was already X-latched in mtr, do not
initialize the page.
xdes_get_descriptor_with_space_hdr(): Assert that the file space
header is being X-latched.
fsp_alloc_from_free_frag(): Refactored from fsp_alloc_free_page().
fsp_page_create(): New function, for allocating, X-latching and
potentially initializing a page. If init_mtr!=mtr but the page was
already X-latched in mtr, do not initialize the page.
fsp_free_page(): Add ut_ad(0) to the error outcomes.
fsp_free_page(), fseg_free_page_low(): Increment mtr->n_freed_pages.
fsp_alloc_seg_inode_page(), fseg_create_general(): Assert that the
page was not previously X-latched in the mini-transaction. A file
segment or inode page should never be allocated in the middle of an
mini-transaction that frees pages, such as btr_cur_pessimistic_delete().
fseg_alloc_free_page_low(): If the hinted page was allocated, skip the
check if the tablespace should be extended. Return NULL instead of
FIL_NULL on failure. Remove the flag frag_page_allocated. Instead,
return directly, because the page would already have been initialized.
fseg_find_free_frag_page_slot() would return ULINT_UNDEFINED on error,
not FIL_NULL. Correct a bogus assertion.
fseg_alloc_free_page(): Redefine as a wrapper macro around
fseg_alloc_free_page_general().
buf_block_buf_fix_inc(): Move the definition from the buf0buf.ic to
buf0buf.h, so that it can be called from other modules.
mtr_t: Add n_freed_pages (number of pages that have been freed).
page_rec_get_nth_const(), page_rec_get_nth(): The inverse function of
page_rec_get_n_recs_before(), get the nth record of the record
list. This is faster than iterating the linked list. Refactored from
page_get_middle_rec().
trx_undo_rec_copy(): Add a debug assertion for the length.
trx_undo_add_page(): Return a block descriptor or NULL instead of a
page number or FIL_NULL.
trx_undo_report_row_operation(): Add debug assertions.
trx_sys_create_doublewrite_buf(): Assert that each page was not
previously X-latched.
page_cur_insert_rec_zip_reorg(): Make use of page_rec_get_nth().
row_ins_clust_index_entry_by_modify(): Pass BTR_KEEP_POS_FLAG, so that
the repositioning of the cursor can be avoided.
row_ins_index_entry_low(): Add DEBUG_SYNC points before and after
writing off-page columns. If inserting by updating a delete-marked
record, do not reposition the cursor or commit the mini-transaction
before writing the off-page columns.
row_build(): Tighten a debug assertion about null BLOB pointers.
row_upd_clust_rec(): Add DEBUG_SYNC points before and after writing
off-page columns. Do not reposition the cursor or commit the
mini-transaction before writing the off-page columns.
rb:939 approved by Jimmy Yang
Problem: Statements that write to tables with auto_increment columns
based on the selection from another table, may lead to master
and slave going out of sync, as the order in which the rows
are retrieved from the table may differ on master and slave.
Solution: We mark writing to a table with auto_increment table
based on the rows selected from another table as unsafe. This
will cause the execution of such statements to throw a warning
and forces the statement to be logged in ROW if the logging
format is mixed.
Changes:
1. All the statements that writes to a table with auto_increment
column(s) based on the rows fetched from another table, will now
be unsafe.
2. CREATE TABLE with SELECT will now be unsafe.
Problem: Statements that write to tables with auto_increment columns
based on the selection from another table, may lead to master
and slave going out of sync, as the order in which the rows
are retrived from the table may differ on master and slave.
Solution: We mark writing to a table with auto_increment table
as unsafe. This will cause the execution of such statements to
throw a warning and forces the statement to be logged in ROW if
the logging format is mixed.
Changes:
1. All the statements that writes to a table with auto_increment
column(s) based on the rows fetched from another table, will now
be unsafe.
2. CREATE TABLE with SELECT will now be unsafe.
IS EXECUTED TWICE FROM P
This bug is a duplicate of bug 12567331, which was pushed to the
optimizer backporting tree on 2011-06-11. This is just a back-port of
the fix. Both test cases are included as they differ somewhat.
The actual Bug#11754376 does not exist in MySQL 5.5 because at startup
we drop entries for temporary tables from InnoDB dictionary cache (only
if ROW_FORMAT is not REDUNDANT). But nevertheless the bug in
normalize_table_name_low() is present so we fix it.
GRACEFUL SHUTDOWN
During startup mysql picks up .frm files from the tmpdir directory and
tries to drop those tables in the storage engine.
The problem is that when tmpdir ends in / then ha_innobase::delete_table()
is passed a string like "/var/tmp//#sql123", then it wrongly normalizes it
to "/#sql123" and calls row_drop_table_for_mysql() which of course fails
to delete the table entry from the InnoDB dictionary cache.
ha_innobase::delete_table() returns an error but nevertheless mysql wipes
away the .frm file and the entry in the InnoDB dictionary cache remains
orphaned with no easy way to remove it.
The "no easy" way to remove it is to create a similar temporary table again,
copy its .frm file to tmpdir under "#sql123.frm" and restart mysqld with
tmpdir=/var/tmp (no trailing slash) - this way mysql will pick the .frm file
after restart and will try to issue drop table for "/var/tmp/#sql123"
(notice do double slash), ha_innobase::delete_table() will normalize it to
"tmp/#sql123" and row_drop_table_for_mysql() will successfully remove the
table entry from the dictionary cache.
The solution is to fix normalize_table_name_low() to normalize things like
"/var/tmp//table" correctly to "tmp/table".
This patch also adds a test function which invokes
normalize_table_name_low() with various inputs to make sure it works
correctly and a mtr test that calls this test function.
Reviewed by: Marko (http://bur03.no.oracle.com/rb/r/929/)
rpl_heartbeat_basic test fails sporadically on pushbuild because did
not received all heartbeats from slave in circular replication.
Removed from experimental collection.
ALTER TABLE AFTER DROP PARTITION
Bug#13608188 - 64038: CRASH IN HANDLER::HA_THD ON ALTER TABLE AFTER
REPAIR NON-EXISTING PARTITION
Backport of bug#13357766 from -trunk to -5.5.
The state of some partitions was not reset on failure, leading
to invalid states of partitions in consequent statements.
Fixed by reverting back to original state for all partitions
if not all partition names was resolved.
Also adding extra security by forcing tables to be reopened
in case of error in mysql_alter_table.
(There is also removal of \r at the end of some lines.)
CASES RESETS DATA POINTER TO SMAL
ISSUE: Myisamchk doing sort recover
on a table reduces data_file_length.
Maximum size of data file decreases,
lesser number of rows are stored.
SOLUTION: Size of data_file_length is
fixed to the original length.
CASES RESETS DATA POINTER TO SMAL
ISSUE: Myisamchk doing sort recover
on a table reduces data_file_length.
Maximum size of data file decreases,
lesser number of rows are stored.
SOLUTION: Size of data_file_length is
fixed to the original length.
