a518e1dd42
1. Access foreign keys via TABLE_SHARE::foreign_keys and
TABLE_SHARE::referenced_keys;
foreign_keys and referenced_keys are lists in TABLE_SHARE.
2. Remove handler FK interface:
- get_foreign_key_list()
- get_parent_foreign_key_list()
- referenced_by_foreign_key()
3. Invalidate referenced shares on:
- RENAME TABLE
- DROP TABLE
- RENAME COLUMN
- ADD FOREIGN KEY
When foreign table is created or altered by the above operations
all referenced shares are closed. This blocks the operation while
any referenced shares are used (when at least one its TABLE
instance is locked).
4. Update referenced shares on:
- CREATE TABLE
On CREATE TABLE add items to referenced_keys of referenced
shares. States of referenced shares are restored in case of errors.
5. Invalidate foreign shares on:
- RENAME TABLE
- RENAME COLUMN
The above-mentioned blocking takes effect.
6. Check foreign/referenced shares consistency on:
- CHECK TABLE
7. Temporary change until MDEV-21051:
InnoDB fill foreign key info at handler open().
FOREIGN_KEY_INFO is refactored to FK_info holding Lex_cstring.
On first TABLE open FK_info is loaded from storage engine into
TABLE_SHARE. All referenced shares (if any exists) are closed. This
leads to blocking of first time foreign table open while referenced
tables are used.
MDEV-21311 Converge Foreign_key and supplemental generated Key together
mysql_prepare_create_table() does data validation and such utilities
as automatic name generation. But it does that only for indexes and
ignores Foreign_key objects. Now as Foreign_key data needs to be
stored in FRM files as well this processing must be done for it like
for any other Key objects.
Replace Key::FOREIGN_KEY type with Key::foreign flag of type
Key::MULTIPLE and Key::generated set to true. Construct one object
with Key::foreign == true instead of two objects of type
Key::FOREIGN_KEY and Key::MULTIPLE.
MDEV-21051 datadict refactorings
- Move read_extra2() to datadict.cc
- Refactored extra2_fields to Extra2_info
- build_frm_image() readability
MDEV-21051 build_table_shadow_filename() refactoring
mysql_prepare_alter_table() leaks fixes
MDEV-21051 amend system tables locking restriction
Table mysql.help_relation has foreign key to mysql.help_keyword. On
bootstrap when help_relation is opened, it preopens help_keyword for
READ and fails in lock_tables_check().
If system table is opened for write then fk references are opened for
write.
Related to: Bug#25422, WL#3984
Tests: main.lock
MDEV-21051 Store and read foreign key info into/from FRM files
1. Introduce Foreign_key_io class which creates/parses binary stream
containing foreign key structures. Referenced tables store there only
hints about foreign tables (their db and name), they restore full info
from the corresponding tables.
Foreign_key_io is stored under new EXTRA2_FOREIGN_KEY_INFO field in
extra2 section of FRM file.
2. Modify mysql_prepare_create_table() to generate names for foreign
keys. Until InnoDB storage of foreign keys is removed, FK names must
be unique across the database: the FK name must be based on table
name.
3. Keep stored data in sync on DDL changes. Referenced tables update
their foreign hints after following operations on foreign tables:
- RENAME TABLE
- DROP TABLE
- CREATE TABLE
- ADD FOREIGN KEY
- DROP FOREIGN KEY
Foreign tables update their foreign info after following operations on
referenced tables:
- RENAME TABLE
- RENAME COLUMN
4. To achieve 3. there must be ability to rewrite extra2 section of
FRM file without full reparse. FRM binary is built from primary
structures like HA_CREATE_INFO and cannot be built from TABLE_SHARE.
Use shadow write and rename like fast_alter_partition_table()
does. Shadow FRM is new FRM file that replaces the old one.
CREATE TABLE workflow:
1. Foreign_key is constructed in parser, placed into
alter_info->key_list;
2. mysql_prepare_create_table() translates them to FK_info, assigns
foreign_id if needed;
3. build_frm_image() writes two FK_info lists into FRM's extra2
section, for referenced keys it stores only table names (hints);
4. init_from_binary_frm_image() parses extra2 section and fills
foreign_keys and referenced_keys of TABLE_SHARE.
It restores referenced_keys by reading hint list of table names,
opening corresponding shares and restoring FK_info from their
foreign_keys. Hints resolution is done only when initializing
non-temporary shares. Usually temporary share has different
(temporary) name and it is impossible to resolve foreign keys by
that name (as we identify them by both foreign and referenced
table names). Another not unimportant reason is performance: this
saves spare share acquisitions.
ALTER TABLE workflow:
1. Foreign_key is constructed in parser, placed into
alter_info->key_list;
2. mysql_prepare_alter_table() prepares action lists and share list
of foreigns/references;
3. mysql_prepare_alter_table() locks list of foreigns/references by
MDL_INTENTION_EXCLUSIVE, acquires shares;
4. prepare_create_table() converts key_list into FK_list, assigns
foreign_id;
5. shadow FRM of altered table is created;
6. data is copied;
7. altered table is locked by MDL_EXCLUSIVE;
8. fk_handle_alter() processes action lists, creates FK backups,
modifies shares, writes shadow FRMs;
9. altered table is closed;
10. shadow FRMs are installed;
11. altered table is renamed, FRM backup deleted;
12. (TBD in MDEV-21053) shadow FRMs installation log closed, backups
deleted;
On FK backup system:
In case of failed DDL operation all shares that was modified must be
restored into original state. This is done by FK_ddl_backup (CREATE,
DROP), FK_rename_backup (RENAME), FK_alter_backup (ALTER).
On STL usage:
STL is used for utility not performance-critical algorithms, core
structures hold native List. A wrapper was made to convert STL
exception into bool error status or NULL value.
MDEV-20865 fk_check_consistency() in CHECK TABLE
Self-refs fix
Test table_flags fix: "debug" deviation is now gone.
FIXMEs: +16 -1
|
||
|---|---|---|
| .. | ||
| charsets | ||
| CMakeLists.txt | ||
| errmsg-utf8.txt | ||
| insert_translations_into_errmsg.py | ||
| README.md | ||
A quicker way for adding new language translations to the errmsg-utf8.txt file
Summary
To generate a new language translation of MariaDB use the following pull request (PR) as a template for your work:
You will notice as part of your translation work, you will have to add your language translations to the file sql/share/errmsg-utf8.txt which is found in the current directory. This file is long with many sections which can make the translation work tedious. In this README, we explain a procedure and provide a script insert_translations_into_errmsg.py that cuts down the amount of tedium in accomplishing the task.
Procedure
-
Start by grepping out all the english translations from errmsg-utf8.txt using the following grep command, and redirecting the output to a file:
grep -P "^\s*eng\s" errmsg-utf8.txt > all_english_text_in_errmsg-utf8.txt
-
Next use Google translate to obtain a translation of this file. Google translate provides the ability to upload whole files for translation. For example, this technique was used to obtain Swahili translations which yielded a file with output similar to the below (output is truncated for clarity):
sw "hashchk" sw "isamchk" sw "LA" sw "NDIYO" sw "Haiwezi kuunda faili '% -.200s' (kosa: %iE)" sw "Haiwezi kuunda jedwali %
s.%s (kosa: %iE)" sw "Haiwezi kuunda hifadhidata '% -.192s' (kosa: %iE)" sw "Haiwezi kuunda hifadhidata '% -.192s'; hifadhidata ipo"
Note that Google translate removes the leading whitespace in the translation file it generates. DO NOT add that leading whitespace back!
-
Give the translated file an appropriate name (e.g.
all_swahili_text_in_errmsg-utf8.txt) and store it in the same directory witherrmsg-utf8.txtandall_english_text_in_errmsg-utf8.txt. These 3 files will be used by the script insert_translations_into_errmsg.py. -
Proof check the auto-translations in the file you downloaded from Google translate. Note that Google might omit formatting information that will cause the compilation of MariaDB to fail, so pay attention to these.
-
Reintegrate these translations into the errmsg-utf8.txt by running the insert_translations_into_errmsg.py script as follows:
chmod ugo+x insert_translations_into_errmsg.py # Make the script executable if it is not.
./insert_translations_into_errmsg.py <errmsg-utf8.txt file>
For example, for the swahili translation, we ran the following:
./insert_translations_into_errmsg.py errmsg-utf8.txt all_english_text_in_errmsg-utf8.txt all_swahili_text_in_errmsg-utf8.txt
The script uses the
errmsg-utf8.txtfile and the grepped english file to keep track of each new translation. It then creates a file in the same directory aserrmsg-utf8.txtwith the nameerrmsg-utf8-with-new-language.txt. -
Check that the reintegration of the new translations into
errmsg-utf8-with-new-language.txtwent OK, and if it did, renameerrmsg-utf8-with-new-language.txttoerrmsg-utf8.txt:mv errmsg-utf8-with-new-language.txt errmsg-utf8.txt
-
In the header of errmsg-utf8.txt make sure to add your language long form to short form mapping. E.g. for Swahili, add:
swahili=sw