Counter for select numbering made stored with the statement (before was global)
So now it does have always accurate value which does not depend on
interruption of statement prepare by errors like lack of table in
a view definition.
This was done in, among other things:
- thd->db and thd->db_length
- TABLE_LIST tablename, db, alias and schema_name
- Audit plugin database name
- lex->db
- All db and table names in Alter_table_ctx
- st_select_lex db
Other things:
- Changed a lot of functions to take const LEX_CSTRING* as argument
for db, table_name and alias. See init_one_table() as an example.
- Changed some function arguments from LEX_CSTRING to const LEX_CSTRING
- Changed some lists from LEX_STRING to LEX_CSTRING
- threads_mysql.result changed because process list_db wasn't always
correctly updated
- New append_identifier() function that takes LEX_CSTRING* as arguments
- Added new element tmp_buff to Alter_table_ctx to separate temp name
handling from temporary space
- Ensure we store the length after my_casedn_str() of table/db names
- Removed not used version of rename_table_in_stat_tables()
- Changed Natural_join_column::table_name and db_name() to never return
NULL (used for print)
- thd->get_db() now returns db as a printable string (thd->db.str or "")
TRASH was mapped to TRASH_FREE and was supposed to be used for memory
that should not be accessed anymore, while TRASH_ALLOC() is to be
used for uninitialized but to-be-used memory.
But sometimes TRASH() was used in the latter sense.
Remove TRASH() macro, always use explicit TRASH_ALLOC() or TRASH_FREE().
Other changes done to get this to work:
- Added 'internal_tables' to TABLE object to list which sequence tables
is needed to use the table.
- Mark any expression using DEFAULT() with LEX->default_used.
This is needed when deciding if we should open internal sequence
tables when a table is opened (we don't need to open sequence tables
if the main table is only used with SELECT).
- Create_and_open_temporary_table() can now also open all internal
sequence tables.
- Added option MYSQL_LOCK_USE_MALLOC to mysql_lock_tables()
to force memory allocation to be used with malloc instead of
memroot.
- Added flag to MYSQL_LOCK to remember if allocation was done with
malloc or memroot (makes code simpler and safer).
- init_one_table_for_prelocking() now takes argument for what lock to
use instead of it's a routine or something else.
- Renamed prelocking placeholders to make them more understandable as
they are now used in more code.
- Changed test in check_lock_and_start_stmt() if found table has correct
locks. The old test didn't work for tables that has lock
TL_WRITE_ALLOW_WRITE, which is what sequence tables are using.
- Added VCOL_NOT_VIRTUAL option to ensure that sequence functions can't
be used with virtual columns
- More sequence tests
This commit implements aggregate stored functions. The basic idea behind
the feature is:
* Implement a special instruction FETCH GROUP NEXT ROW that will pause
the execution of the stored function. When the instruction is reached,
execution of the initial query resumes "as if" the function returned.
This gives the server the opportunity to advance to the next row in the
result set.
* Stored aggregates behave like regular aggregate functions. The
implementation of thus resides in the class Item_sum_sp. Because it is
an aggregate function, for each new row in the group, the
Item_sum_sp::add() method will be called. This is when execution resumes
and the function does another iteration to "add" one extra element to
the final result.
* When the end of group is reached, val_xxx() method will be called for
the item. This case is handled by another execute step for the stored
function, only with a special flag to force a call to the return
handler. See Item_sum_sp::execute() for details.
To allow this pause and resume semantic, we must preserve the function
context across executions. This is stored in Item_sp::sp_query_arena only for
aggregate stored functions, but has no impact for regular functions.
We also enforce aggregate functions to include the "FETCH GROUP NEXT ROW"
instruction.
Signed-off-by: Vicențiu Ciorbaru <vicentiu@mariadb.org>
Most "new" failures fixed in the following files:
- sql_select.cc
- item.cc
- item_func.cc
- opt_subselect.cc
Other things:
- Allocate udf_handler strings in mem_root
- Required changes in sql_string.h
- Add mem_root as argument to some new [] calls
- Mark udf_handler strings as thread specific
- Removed some comment blocks with code
Issue:
------
VALUES doesn't have a type() function and is considered a
Item_field.
Solution for 5.7:
-----------------
Add a new type() function for Item_values_insert.
On 8.0 and trunk it was fixed by Mithun's Bug#19601973.
Solution for 5.6:
-----------------
Additionally Bug#17458914 is backported.
This will address the problem of using VALUES() in
INSERT ... ON DUPLICATE KEY UPDATE. Create a field object
only if it is in the UPDATE clause, else return a NULL
item.
This will also address the problems mentioned in
Bug#14789787 and Bug#16756402.
Solution for 5.5:
-----------------
As mentioned above Bug#17458914 is backported.
Additionally Bug#14786324 is also backported.
When VALUES() is detected outside its meaningful place,
it should be treated as NULL and is thus replaced with a
Field_null object, with the same name as the original
field.
Fields with type NULL are generally not handled well inside
the server (e.g Innodb will not accept them and it is
impossible to create them in regular tables). So create a
new const NULL item instead.
As reported in MDEV-11969 "there's no way to ditch knowledge" about some
domain that is no longer updated on a server. Besides being of annoyance to
clutter output in DBA console stale domains can prevent the slave
to connect the master as MDEV-12012 witnesses.
What domain is obsolete must be evaluated by the user (DBA) according
to whether the domain info is still relevant and will the domain ever
receive any update.
This patch introduces a method to discard obsolete gtid domains from
the server binlog state. The removal requires no event group from such
domain present in existing binlog files though. If there are any the
containing logs must be first PURGEd in order for
FLUSH BINARY LOGS DELETE_DOMAIN_ID=(list-of-domains)
succeed. Otherwise the command returns an error.
The list of obsolete domains can be computed through
intersecting two sets - the earliest (first) binlog's Gtid_list
and the current value of @@global.gtid_binlog_state - and extracting
the domain id components from the intersection list items.
The new DELETE_DOMAIN_ID featured FLUSH continues to rotate binlog
omitting the deleted domains from the active binlog file's Gtid_list.
Notice though when the command is ineffective - that none of requested to delete
domain exists in the binlog state - rotation does not occur.
Obsolete domain deletion is not harmful for connected slaves as long
as master side binlog files *purge* is synchronized with FLUSH-DELETE_DOMAIN_ID.
The slaves must have the last event from purged files processed as usual,
in order not to bump later into requesting a gtid from a file which
was already gone.
While the command is not replicated (as ordinary FLUSH BINLOG LOGS is)
slaves, even though having extra domains, won't suffer from reconnection errors
thanks to master-slave gtid connection protocol allowing the master
to be ignorant about a gtid domain.
Should at failover such slave to be promoted into master role it may run
the ex-master's
FLUSH BINARY LOGS DELETE_DOMAIN_ID=(list-of-domains)
to clean its own binlog state.
NOTES.
suite/perfschema/r/start_server_low_digest.result
is re-recorded as consequence of internal parser codes changes.
As a result of this merge the code for the following tasks appears in 10.3:
- MDEV-12172 Implement tables specified by table value constructors
- MDEV-12176 Transform [NOT] IN predicate with long list of values INTO
[NOT] IN subquery.
A reference to a CTE may occur not in the master of the CTE
specification. In this case if the reference to the CTE is
the first one the specification should be detached from its
master and attached to the referencing select.
Also fixed the TYPE column in the lines of the EXPLAIN output
created for CTE tables.
