In particular:
* @@debug
deprecated since 5.5.37
* sr_YU locale
deprecated since 10.0.11
* "engine_condition_pushdown" in the @@optimizer_switch
deprecated since 10.1.1
* @@date_format, @@datetime_format, @@time_format, @@max_tmp_tables
deprecated since 10.1.2
* @@wsrep_causal_reads
deprecated since 10.1.3
* "parser" in mroonga table comment
deprecated since 10.2.11
The used code is largely based on code from Tencent
The problem is that in some rare cases there may be a conflict between .frm
files and the files in the storage engine. In this case the DROP TABLE
was not able to properly drop the table.
Some MariaDB/MySQL forks has solved this by adding a FORCE option to
DROP TABLE. After some discussion among MariaDB developers, we concluded
that users expects that DROP TABLE should always work, even if the
table would not be consistent. There should not be a need to use a
separate keyword to ensure that the table is really deleted.
The used solution is:
- If a .frm table doesn't exists, try dropping the table from all storage
engines.
- If the .frm table exists but the table does not exist in the engine
try dropping the table from all storage engines.
- Update storage engines using many table files (.CVS, MyISAM, Aria) to
succeed with the drop even if some of the files are missing.
- Add HTON_AUTOMATIC_DELETE_TABLE to handlerton's where delete_table()
is not needed and always succeed. This is used by ha_delete_table_force()
to know which handlers to ignore when trying to drop a table without
a .frm file.
The disadvantage of this solution is that a DROP TABLE on a non existing
table will be a bit slower as we have to ask all active storage engines
if they know anything about the table.
Other things:
- Added a new flag MY_IGNORE_ENOENT to my_delete() to not give an error
if the file doesn't exist. This simplifies some of the code.
- Don't clear thd->error in ha_delete_table() if there was an active
error. This is a bug fix.
- handler::delete_table() will not abort if first file doesn't exists.
This is bug fix to handle the case when a drop table was aborted in
the middle.
- Cleaned up mysql_rm_table_no_locks() to ensure that if_exists uses
same code path as when it's not used.
- Use non_existing_Table_error() to detect if table didn't exists.
Old code used different errors tests in different position.
- Table_triggers_list::drop_all_triggers() now drops trigger file if
it can't be parsed instead of leaving it hanging around (bug fix)
- InnoDB doesn't anymore print error about .frm file out of sync with
InnoDB directory if .frm file does not exists. This change was required
to be able to try to drop an InnoDB file when .frm doesn't exists.
- Fixed bug in mi_delete_table() where the .MYD file would not be dropped
if the .MYI file didn't exists.
- Fixed memory leak in Mroonga when deleting non existing table
- Fixed memory leak in Connect when deleting non existing table
Bugs fixed introduced by the original version of this commit:
MDEV-22826 Presence of Spider prevents tables from being force-deleted from
other engines
Use thd_get_ha_data()/thd_set_ha_data() which protect against plugin
removal until it has THD ha_data.
Do not reset THD ha_data in mrn_close_connection(), cleaner approach
is to let ha_close_connection() do it.
Part of MDEV-19515 - Improve connect speed
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 "")
Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)
Changes:
- This caused some ABI changes
- lex_string_set now uses LEX_CSTRING
- Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
code
- Added item_empty_name and item_used_name to be able to distingush between
items that was given an empty name and items that was not given a name
This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
give the error.
TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
(as part of lower_case_table_names)
- Removed some QQ markers
- Removed some rows not compatible with valgrind 3.9.0
- Made mysql_install_db.sh more silent by default. --verbose now gives more information
- Added assert that auto-increment doesn't generate 0 (safety)
- Removed thd->set_time() in some places as it's set in init_for_queries()
- Fixed some --big tests in tokudb
- Fixed a bug in mysql_client_test.cc where sql_mode was not properly reset
