Define my_thread_id as an unsigned type, to avoid mismatch with
ulonglong. Change some parameters to this type.
Use size_t in a few more places.
Declare many flag constants as unsigned to avoid sign mismatch
when shifting bits or applying the unary ~ operator.
When applying the unary ~ operator to enum constants, explictly
cast the result to an unsigned type, because enum constants can
be treated as signed.
In InnoDB, change the source code line number parameters from
ulint to unsigned type. Also, make some InnoDB functions return
a narrower type (unsigned or uint32_t instead of ulint;
bool instead of ibool).
==== Description ====
Flashback can rollback the instances/databases/tables to an old snapshot.
It's implement on Server-Level by full image format binary logs (--binlog-row-image=FULL), so it supports all engines.
Currently, it’s a feature inside mysqlbinlog tool (with --flashback arguments).
Because the flashback binlog events will store in the memory, you should check if there is enough memory in your machine.
==== New Arguments to mysqlbinlog ====
--flashback (-B)
It will let mysqlbinlog to work on FLASHBACK mode.
==== New Arguments to mysqld ====
--flashback
Setup the server to use flashback. This enables binary log in row mode
and will enable extra logging for DDL's needed by flashback feature
==== Example ====
I have a table "t" in database "test", we can compare the output with "--flashback" and without.
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" > /tmp/1.sql
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" -B > /tmp/2.sql
Then, importing the output flashback file (/tmp/2.log), it can flashback your database/table to the special time (--start-datetime).
And if you know the exact postion, "--start-postion" is also works, mysqlbinlog will output the flashback logs that can flashback to "--start-postion" position.
==== Implement ====
1. As we know, if binlog_format is ROW (binlog-row-image=FULL in 10.1 and later), all columns value are store in the row event, so we can get the data before mis-operation.
2. Just do following things:
2.1 Change Event Type, INSERT->DELETE, DELETE->INSERT.
For example:
INSERT INTO t VALUES (...) ---> DELETE FROM t WHERE ...
DELETE FROM t ... ---> INSERT INTO t VALUES (...)
2.2 For Update_Event, swapping the SET part and WHERE part.
For example:
UPDATE t SET cols1 = vals1 WHERE cols2 = vals2
--->
UPDATE t SET cols2 = vals2 WHERE cols1 = vals1
2.3 For Multi-Rows Event, reverse the rows sequence, from the last row to the first row.
For example:
DELETE FROM t WHERE id=1; DELETE FROM t WHERE id=2; ...; DELETE FROM t WHERE id=n;
--->
DELETE FROM t WHERE id=n; ...; DELETE FROM t WHERE id=2; DELETE FROM t WHERE id=1;
2.4 Output those events from the last one to the first one which mis-operation happened.
For example:
Most notably, this includes MDEV-11623, which includes a fix and
an upgrade procedure for the InnoDB file format incompatibility
that is present in MariaDB Server 10.1.0 through 10.1.20.
In other words, this merge should address
MDEV-11202 InnoDB 10.1 -> 10.2 migration does not work
Tasks:-
Changes in wsrep_dirty_reads variable
1.) Global + Session scope (Current: session-only)
2.) Can be set using command line.
3.) Allow all commands that do not change data (besides SELECT)
4.) Allow prepared Statements that do not change data
5.) Works with wsrep_sync_wait enabled
Increase max number of possible table_open_cache instances from 512K
to 1024K. This only affects user who are trying to set the variable over
the old limit.
Delete not used test table_open_cache_instances_basic
(Need to be added back and rewritten in 10.2)
This has no functional changes, but it helps avoid merge problems from 10.0
to 10.1. In 10.0, code that checks for parallel replication uses
opt_slave_parallel_threads > 0, but this check needs to be
mi->using_parallel() in 10.1. By using the same check in 10.0 (with
unchanged semantics), merge problems to 10.1 are avoided.
Add some event types for the compressed event, there are:
QUERY_COMPRESSED_EVENT,
WRITE_ROWS_COMPRESSED_EVENT_V1,
UPDATE_ROWS_COMPRESSED_EVENT_V1,
DELETE_POWS_COMPRESSED_EVENT_V1,
WRITE_ROWS_COMPRESSED_EVENT,
UPDATE_ROWS_COMPRESSED_EVENT,
DELETE_POWS_COMPRESSED_EVENT.
These events inheritance the uncompressed editor events. One of their constructor functions and write
function have been overridden for uncompressing and compressing. Anything but this is totally the same.
On slave, The IO thread will uncompress and convert them When it receiving the events from the master.
So the SQL and worker threads can be stay unchanged.
Now we use zlib as compress algorithm. It maybe support other algorithm in the future.
This is similar to MysQL Worklog 3253, but with
a different implementation. The disk format and
SQL syntax is identical with MySQL 5.7.
Fetures supported:
- "Any" ammount of any trigger
- Supports FOLLOWS and PRECEDES to be
able to put triggers in a certain execution order.
Implementation details:
- Class Trigger added to hold information about a trigger.
Before this trigger information was stored in a set of lists in
Table_triggers_list and in Table_triggers_list::bodies
- Each Trigger has a next field that poinst to the next Trigger with the
same action and time.
- When accessing a trigger, we now always access all linked triggers
- The list are now only used to load and save trigger files.
- MySQL trigger test case (trigger_wl3253) added and we execute these
identically.
- Even more gracefully handling of wrong trigger files than before. This
is useful if a trigger file uses functions or syntax not provided by
the server.
- Each trigger now has a "Created" field that shows when the trigger was
created, with 2 decimals.
Other comments:
- Many of the changes in test files was done because of the new "Created"
field in the trigger file. This shows up in SHOW ... TRIGGER and when
using information_schema.trigger.
- Don't check if all memory is released if on uses --gdb; This is needed
to be able to get a list from safemalloc of not freed memory while
debugging.
- Added option to trim_whitespace() to know how many prefix characters
was skipped.
- Changed a few ulonglong sql_mode to sql_mode_t, to find some wrong usage
of sql_mode.
Fixed sysvars_server_[not]embedded failure: changed type of
table_open_cache_instances from ulong to uint.
Added casts foratomic operations around tc_active_instances and
tc_contention_warning_reported: needed on some platforms.
This makes it easier to setup master as on only have to set --log-bin.
Before this patch if one did set up the master with just --log-bin, slaves
could not connect until server_id was set on the master, which could be
both confusing and hard to do.
In well defined C code, the "this" pointer is never NULL. Currently, we
were potentially dereferencing a NULL pointer (master_info_index). GCC v6
removes any "if (!this)" conditions as it assumes this is always a
non-null pointer. In order to prevent undefined behaviour, check the
pointer before dereferencing and remove the check within member
functions.
Moved checking whether the limit set for the number of iterations
when executing a recursive query has been reached from
st_select_lex_unit::exec_recursive to TABLE_LIST::fill_recursive.
Changed the name of the system variable max_recursion_level for
max_recursive_iterations.
Adjusted test cases.
