This commit adds a new feature to the server to add comments at the database
level. 1024 bytes is the maximum comment length allowed. If the comment length
exceeds this limit, a new error/warning code 4144 is thrown, based on whether
thd->is_strict_mode() is true/false. The database comment is also added to the
db.opt file, as well as to the information_schema.schemata table.
make live checksum to be returned in handler::info(),
and slow table-scan checksum to be calculated in handler::checksum().
part of
MDEV-16249 CHECKSUM TABLE for a spider table is not parallel and saves all data in memory in the spider head by default
This patch fixes an invalid read in fill_effective_table_privileges
triggered by a grant_version increase between a PREPARE for a
statement creating a view from I_S and EXECUTE.
A tmp table was created and free'd while preparing the statement,
TABLE_LIST::table_name was set to point to the tmp table
TABLE_SHARE::table_name which no longer existed after preparing was
done.
The grant version increase made fill_effective_table_privileges
called during EXECUTE to try fetch the updated grant info and
this is where the dangling table name was used.
The command SHOW INDEXES ignored setting of the system variable
use_stat_tables to the value of 'preferably' and and showed statistical
data received from the engine. Similarly queries over the table
STATISTICS from INFORMATION_SCHEMA ignored this setting. It happened
because the function fill_schema_table_by_open() did not read any data
from statistical tables.
This patch was originally made by Anel Husakovic.
Skip `PACKAGE` and `PACKAGE BODY` records quickly.
These stored objects do not have any parameters or return values
(only procedures and functions have).
So no needs to build a `CREATE` statement
(in `Sp_handler::sp_load_for_information_schema()`) and parse it:
this won't give us any data useful for `INFORMATION_SCHEMA.PARAMETERS`.
The MDEV-17262 commit 26432e49d3
was skipped. In Galera 4, the implementation would seem to require
changes to the streaming replication.
In the tests archive.rnd_pos main.profiling, disable_ps_protocol
for SHOW STATUS and SHOW PROFILE commands until MDEV-18974
has been fixed.
There were two newly enabled warnings:
1. cast for a function pointers. Affected sql_analyse.h, mi_write.c
and ma_write.cc, mf_iocache-t.cc, mysqlbinlog.cc, encryption.cc, etc
2. memcpy/memset of nontrivial structures. Fixed as:
* the warning disabled for InnoDB
* TABLE, TABLE_SHARE, and TABLE_LIST got a new method reset() which
does the bzero(), which is safe for these classes, but any other
bzero() will still cause a warning
* Table_scope_and_contents_source_st uses `TABLE_LIST *` (trivial)
instead of `SQL_I_List<TABLE_LIST>` (not trivial) so it's safe to
bzero now.
* added casts in debug_sync.cc and sql_select.cc (for JOIN)
* move assignment method for MDL_request instead of memcpy()
* PARTIAL_INDEX_INTERSECT_INFO::init() instead of bzero()
* remove constructor from READ_RECORD() to make it trivial
* replace some memcpy() with c++ copy assignments
Make mysqltest to use --ps-protocol more
use prepared statements for everything that server supports
with the exception of CALL (for now).
Fix discovered test failures and bugs.
tests:
* PROCESSLIST shows Execute state, not Query
* SHOW STATUS increments status variables more than in text protocol
* multi-statements should be avoided (see tests with a wrong delimiter)
* performance_schema events have different names in --ps-protocol
* --enable_prepare_warnings
mysqltest.cc:
* make sure run_query_stmt() doesn't crash if there's
no active connection (in wait_until_connected_again.inc)
* prepare all statements that server supports
protocol.h
* Protocol_discard::send_result_set_metadata() should not send
anything to the client.
sql_acl.cc:
* extract the functionality of getting the user for SHOW GRANTS
from check_show_access(), so that mysql_test_show_grants() could
generate the correct column names in the prepare step
sql_class.cc:
* result->prepare() can fail, don't ignore its return value
* use correct number of decimals for EXPLAIN columns
sql_parse.cc:
* discard profiling for SHOW PROFILE. In text protocol it's done in
prepare_schema_table(), but in --ps it is called on prepare only,
so nothing was discarding profiling during execute.
* move the permission checking code for SHOW CREATE VIEW to
mysqld_show_create_get_fields(), so that it would be called during
prepare step too.
* only set sel_result when it was created here and needs to be
destroyed in the same block. Avoid destroying lex->result.
* use the correct number of tables in check_show_access(). Saying
"as many as possible" doesn't work when first_not_own_table isn't
set yet.
sql_prepare.cc:
* use correct user name for SHOW GRANTS columns
* don't ignore verbose flag for SHOW SLAVE STATUS
* support preparing REVOKE ALL and ROLLBACK TO SAVEPOINT
* don't ignore errors from thd->prepare_explain_fields()
* use select_send result for sending ANALYZE and EXPLAIN, but don't
overwrite lex->result, because it might be needed to issue execute-time
errors (select_dumpvar - too many rows)
sql_show.cc:
* check grants for SHOW CREATE VIEW here, not in mysql_execute_command
sql_view.cc:
* use the correct function to check privileges. Old code was doing
check_access() for thd->security_ctx, which is invoker's sctx,
not definer's sctx. Hide various view related errors from the invoker.
sql_yacc.yy:
* initialize lex->select_lex for LOAD, otherwise it'll contain garbage
data that happen to fail tests with views in --ps (but not otherwise).
The problem happened because Item_ident_for_show did not implement val_native().
Solution:
- Removing class Item_ident_for_show
- Implementing a new method Protocol::send_list_fields() instead,
which accepts a List<Field> instead of List<Item> as input.
Now no any Item creation is done during mysqld_list_fields().
Adding helper methods, to reuse the code easier:
- Moved a part of Protocol::send_result_set_metadata(),
responsible for sending an individual field metadata,
into a new method Protocol_text::store_field_metadata().
Reusing it in both send_list_fields() and send_result_set_metadata().
- Adding Protocol_text::store_field_metadata()
- Adding Protocol_text::store_field_metadata_for_list_fields()
Note, this patch also automatically fixed another bug:
MDEV-18685 mysql_list_fields() returns DEFAULT 0 instead of DEFAULT NULL for view columns
The reason for this bug was that Item_ident_for_show::val_xxx() and get_date()
did not check field->is_null() before calling field->val_xxx()/get_date().
Now the default value is correctly sent by Protocol_text::store(Field*).
This patch implements engine independent unique hash index.
Usage:- Unique HASH index can be created automatically for blob/varchar/test column whose key
length > handler->max_key_length()
or it can be explicitly specified.
Automatic Creation:-
Create TABLE t1 (a blob unique);
Explicit Creation:-
Create TABLE t1 (a int , unique(a) using HASH);
Internal KEY_PART Representations:-
Long unique key_info will have 2 representations.
(lets understand this with an example create table t1(a blob, b blob , unique(a, b)); )
1. User Given Representation:- key_info->key_part array will be similar to what user has defined.
So in case of example it will have 2 key_parts (a, b)
2. Storage Engine Representation:- In this case there will be only one key_part and it will point to
HASH_FIELD. This key_part will be always after user defined key_parts.
So:- User Given Representation [a] [b] [hash_key_part]
key_info->key_part ----^
Storage Engine Representation [a] [b] [hash_key_part]
key_info->key_part ------------^
Table->s->key_info will have User Given Representation, While table->key_info will have Storage Engine
Representation.Representation can be changed into each other by calling re/setup_keyinfo_hash function.
Working:-
1. So when user specifies HASH_INDEX or key_length is > handler->max_key_length(), In mysql_prepare_create_table
One extra vfield is added (for each long unique key). And key_info->algorithm is set to HA_KEY_ALG_LONG_HASH.
2. In init_from_binary_frm_image values for hash_keypart is set (like fieldnr , field and flags)
3. In parse_vcol_defs, HASH_FIELD->vcol_info is created. Item_func_hash is used with list of Item_fields,
When Explicit length is given by user then Item_left is used to concatenate Item_field values.
4. In ha_write_row/ha_update_row check_duplicate_long_entry_key is called which will create the hash key from
table->record[0] and then call ha_index_read_map , if we found duplicated hash , we will compare the result
field by field.
This task involves the implementation for the optimizer trace.
This feature produces a trace for any SELECT/UPDATE/DELETE/,
which contains information about decisions taken by the optimizer during
the optimization phase (choice of table access method, various costs,
transformations, etc). This feature would help to tell why some decisions were
taken by the optimizer and why some were rejected.
Trace is session-local, controlled by the @@optimizer_trace variable.
To enable optimizer trace we need to write:
set @@optimizer_trace variable= 'enabled=on';
To display the trace one can run:
SELECT trace FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
This task also involves:
MDEV-18489: Limit the memory used by the optimizer trace
introduces a switch optimizer_trace_max_mem_size which limits
the memory used by the optimizer trace. This was implemented by
Sergei Petrunia.
fill_status.
Also, remove LOCK_status around calc_sum_of_all_status()
Also, rename LOCK_show_status into LOCK_all_status_vars.
This reflects the variable the lock protects.
Implemented and integrated THD_list as a replacement for the global
thread list. It uses own mutex instead of LOCK_thread_count for THD
list protection.
Removed unused first_global_thread() and next_global_thread().
delayed_insert_threads is now protected by LOCK_delayed_insert. Although
this patch doesn't fix very wrong synchronization of this variable.
After this patch there are only 2 legitimate uses of LOCK_thread_count
left, both in mysqld.cc: thread_count and ready_to_exit.
Aim is to reduce usage of LOCK_thread_count and COND_thread_count.
Part of MDEV-15135.
Implement according to standard SQL specification 2008.
The check_constraints table is used for fetching metadata about
the constraints defined for tables in all databases.
There were some result files which failed after running mtr.
These files are updated with newly create record with mtr --record.
