Step 1:
-- Remove page encryption from dictionary (per table
encryption will be handled by storing crypt_data to page 0)
-- Remove encryption/compression from os0file and all functions
before that (compression will be added to buf0buf.cc)
-- Use same CRYPT_SCHEME_1 for all encryption methods
-- Do some code cleanups to confort InnoDB coding style
PROBLEM
Create time is calculated as last status change time of .frm file.
The first problem was that innodb was passing file name as
"table_name#po#p0.frm" to the stat() call which calculates the create time.
Since there is no frm file with this name create_time will be stored as NULL.
The second problem is ha_partition::info() updates stats for create time
when HA_STATUS_CONST flag was set ,where as innodb calculates this statistic
when HA_STATUS_TIME is set,which causes create_time to be set as NULL.
Fix
Pass proper .frm name to stat() call and calculate create time when
HA_STATUS_CONST flag is set.
Analysis: MySQL table definition contains also virtual columns. Similarly,
index fielnr references MySQL table fields. However, InnoDB table definition
does not contain virtual columns. Therefore, when matching MySQL key fieldnr
we need to use actual column name to find out referenced InnoDB dictionary
column name.
Fix: Add new function to match MySQL index key columns to InnoDB dictionary.
available space on disk
Add error handling when disk full situation happens and
intentionally bring server down with stacktrace because
on all cases InnoDB can't continue anyway.
Analysis: On master when executing (single/multi) row INSERTs/REPLACEs
InnoDB fallback to old style autoinc locks (table locks)
only if another transaction has already acquired the AUTOINC lock.
Instead on slave as we are executing log_events and sql_command
is not correctly set, InnoDB does not use new style autoinc
locks when it could.
Fix: Use new style autoinc locks also when
thd_sql_command(user_thd) == SQLCOM_END i.e. this is RBR event.
ISSUE:
------
There can be up to MERGEBUFF2 number of sorted merge chunks,
We need enough buffer space for at least one record from
each merge chunks. If estimates are wrong(very low) and we
allocate buffer space for less than MERGEBUFF2, then we will
have issue in merge_buffers, if actual number of rows to be
sorted is bigger than estimate and external filesort is
chosen.
SOLUTION:
---------
Set number of rows to sort to be at least MERGEBUFF2.
MDEV-7399: Add support for INFORMATION_SCHEMA.INNODB_MUTEXES
MDEV-7618: Improve semaphore instrumentation
Introduced two new information schema tables to monitor mutex waits
and semaphore waits. Added a new configuration variable
innodb_intrument_semaphores to add thread_id, file name and
line of current holder of mutex/rw_lock.
CRASHES ON EVERY START ATTEMPT
Description:
------------
push_warning_printf function is used to print the warning message
to the client. So this function should not invoke while recovering
the server. Moreover current_thd is NULL while starting the server.
Solution:
---------
- Avoiding the warning to be printed while recovery.
This patch already pushed in mysql-5.6.
Use traditional statistics estimation by default (innodb-stats-traditional=true).
There could be performance regression for customers if there is a lot of
open table operations.
innodb_stats_sample_pages
Analysis: If you set the number of analyzed pages
to very low number compared to actual pages on
that table/index it randomly pics those pages
(default 8 pages), this leads to fact that query
after analyze table returns different results. If
the index tree is small, smaller than 10 *
n_sample_pages + total_external_size, then the
estimate is ok. For bigger index trees it is
common that we do not see any borders between
key values in the few pages we pick. But still
there may be n_sample_pages different key values,
or even more. And it just tries to
approximate to n_sample_pages (8).
Fix: (1) Introduced new dynamic configuration variable
innodb_stats_sample_traditional that retains
the current design. Default false.
(2) If traditional sample is not used we use
n_sample_pages = max(min(srv_stats_sample_pages,
index->stat_index_size),
log2(index->stat_index_size)*
srv_stats_sample_pages);
(3) Introduced new dynamic configuration variable
stat_modified_counter (default = 0) if set
sets lower bound for row updates when statistics is re-estimated.
If user has provided upper bound for how many rows needs to be updated
before we calculate new statistics we use minimum of provided value
and 1/16 of table every 16th round. If no upper bound is provided
(srv_stats_modified_counter = 0, default) then calculate new statistics
if 1 / 16 of table has been modified
since the last time a statistics batch was run.
We calculate statistics at most every 16th round, since we may have
a counter table which is very small and updated very often.
@param t table
@return true if the table has changed too much and stats need to be
recalculated
*/
#define DICT_TABLE_CHANGED_TOO_MUCH(t) \
((ib_int64_t) (t)->stat_modified_counter > (srv_stats_modified_counter ? \
ut_min(srv_stats_modified_counter, (16 + (t)->stat_n_rows / 16)) : \
16 + (t)->stat_n_rows / 16))
Problem is that page compressed tables currently require atomic_blobs and
that feature is not availabe currently for row_format=redundant.
Fix: Disallow page compressed create option if table row_format=redundant.
ALTER TABLE: don't fill default values per row, do it once.
And do it in two places - for copy_data_between_tables() and for online ALTER.
Also, run function_defaults test both for MyISAM and for InnoDB.
Merge Facebook commit cd063ab930
authored by Peng Tian from https://github.com/facebook/mysql-5.6
Introduced a new configuration variable innodb_fatal_semaphore_wait_threshold,
it makes the fatal semaphore timeout configurable. Modified original commit
so that no MariaDB server files are changed, instead introduced a new
InnoDB/XtraDB configuration variable.
Its default/min/max vlaues are 600/1/2^32-1 in seconds (it was hardcoded
as 600, now its default value is 600, so the default behavior of this diff
should be no change).
