The problem described in the bug report happened because the code
did not test check_cols(1) after fix_fields() in a few places.
Additionally, fix_fields() could be called multiple times for SP variables,
because they are all fixed at a early stage in append_for_log().
Solution:
1. Adding a few helper methods
- fix_fields_if_needed()
- fix_fields_if_needed_for_scalar()
- fix_fields_if_needed_for_bool()
- fix_fields_if_needed_for_order_by()
and using it in many cases instead of fix_fields() where
the "fixed" status is not definitely known to be "false".
2. Adding DBUG_ASSERT(!fixed) into Item_splocal*::fix_fields()
to catch double execution.
3. Adding tests.
As a good side effect, the patch removes a lot of duplicate code (~60 lines):
if (!item->fixed &&
item->fix_fields(..) &&
item->check_cols(1))
return true;
Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.
This fix excludes rocksdb, spider,spider, sphinx and connect for now.
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 "")
Merge branch '10.3' into trunk
Both field_visibility and VERS_HIDDEN_FLAG exist independently.
TODO:
VERS_HIDDEN_FLAG should be replaced with SYSTEM_INVISIBLE (or COMPLETELY_INVISIBLE?).
Feature Definition:-
This feature adds invisible column functionality to server.
There is 4 level of "invisibility":
1. Not invisible (NOT_INVISIBLE) — Normal columns created by the user
2. A little bit invisible (USER_DEFINED_INVISIBLE) — columns that the
user has marked invisible. They aren't shown in SELECT * and they
don't require values in INSERT table VALUE (...). Otherwise
they behave as normal columns.
3. More invisible (SYSTEM_INVISIBLE) — Can be queried explicitly,
otherwise invisible from everything. Think ROWID sytem column.
Because they're invisible from ALTER TABLE and from CREATE TABLE
they cannot be created or dropped, they're created by the system.
User cant not create a column name which is same as of
SYSTEM_INVISIBLE.
4. Very invisible (COMPLETELY_INVISIBLE) — as above, but cannot be
queried either. They can only show up in EXPLAIN EXTENDED (might
be possible for a very invisible indexed virtual column) but
otherwise they don't exist for the user.If user creates a columns
which has same name as of COMPLETELY_INVISIBLE then
COMPLETELY_INVISIBLE column is renamed again. So it is completely
invisible from user.
Invisible Index(HA_INVISIBLE_KEY):-
Creation of invisible columns require a new type of index which
will be only visible to system. User cant see/alter/create/delete
this index. If user creates a index which is same name as of
invisible index then it will be renamed.
Syntax Details:-
Only USER_DEFINED_INVISIBLE column can be created by user. This
can be created by adding INVISIBLE suffix after column definition.
Create table t1( a int invisible, b int);
Rules:-
There are some rules/restrictions related to use of invisible columns
1. All the columns in table cant be invisible.
Create table t1(a int invisible); \\error
Create table t1(a int invisible, b int invisble); \\error
2. If you want invisible column to be NOT NULL then you have to supply
Default value for the column.
Create table t1(a int, b int not null); \\error
3. If you create a view/create table with select * then this wont copy
invisible fields. So newly created view/table wont have any invisible
columns.
Create table t2 as select * from t1;//t2 wont have t1 invisible column
Create view v1 as select * from t1;//v1 wont have t1 invisible column
4. Invisibility wont be forwarded to next table in any case of create
table/view as select */(a,b,c) from table.
Create table t2 as select a,b,c from t1; // t2 will have t1 invisible
// column(b), but this wont be invisible in t2
Create view v1 as select a,b,c from t1; // v1 will have t1 invisible
// column(b), but this wont be invisible in v1
Implementation Details:-
Parsing:- INVISIBLE_SYM is added into vcol_attribute(so its like unique
suffix), It is also added into keyword_sp_not_data_type so that table
can have column with name invisible.
Implementation detail is given by each modified function/created function.
(Some function are left as they were self explanatory)
(m= Modified, n= Newly Created)
mysql_prepare_create_table(m):- Extra checks for invisible columns are
added. Also some DEBUG_EXECUTE_IF are also added for test cases.
mysql_prepare_alter_table(m):- Now this will drop all the
COMPLETELY_INVISIBLE column and HA_INVISIBLE_KEY index. Further
Modifications are made to stop drop/change/delete of SYSTEM_INVISIBLE
column.
build_frm_image(m):- Now this allows incorporating field_visibility
status into frm image. To remain compatible with old frms
field_visibility info will be only written when any of the field is
not NOT_INVISIBLE.
extra2_write_additional_field_properties(n):- This will write field
visibility info into buffer. We first write EXTRA2_FIELD_FLAGS into
buffer/frm , then each next char will have field_visibility for each
field.
init_from_binary_frm_image(m):- Now if we get EXTRA2_FIELD_FLAGS,
then we will read the next n(n= number of fields) chars and set the
field_visibility. We also increment
thd->status_var.feature_invisible_columns. One important thing to
note if we find out that key contains a field whose visibility is
> USER_DEFINED_INVISIBLE then , we declare this key as invisible
key.
sql_show.cc is changed accordingly to make show table, show keys
correct.
mysql_insert(m):- If we get to know that we are doing insert in
this way insert into t1 values(1,1); without explicitly specifying
columns, then we check for if we have invisible fields if yes then
we reset the whole record, Why ? Because first we want hidden columns
to get default/null value. Second thing auto_increment has property
no default and no null which voilates invisible key rule 2, And
because of this it was giving error. Reseting table->record[0]
eliminates this issue. More info put breakpoint on handler::write_row
and see auto_increment value.
fill_record(m):- we continue loop if we find invisible column because
this is already reseted/will get its value if it is default.
Test cases:- Since we can not directly add > USER_DEFINED_INVISIBLE
column then I have debug_dbug to create it in mysql_prepare_create_table.
Patch Credit:- Serg Golubchik
UNEXPECTED ERROR
ANALYSIS:
=========
Creating many indexes with large amount of index
information causes a server exit.
FIX:
====
A appropriate error is reported when the cumulative index
information length exceeds the 2 byte range (i.e 65535).
- Fix win64 pointer truncation warnings
(usually coming from misusing 0x%lx and long cast in DBUG)
- Also fix printf-format warnings
Make the above mentioned warnings fatal.
- fix pthread_join on Windows to set return value.
- Simplified use_trans_cache() to return at once if is_transactional is set
- Indentation and spelling errors fixed
- Don't call signal_update() if update_binlog_end_pos() is called as the
function already calls signal_update()
- Removed not used function wait_for_update_bin_log(), which would cause
errors if ever used.
- Simplified handler::clone() by always allocating 'ref' in ha_open(). To do
this I added an optional MEM_ROOT argument to ha_open() to be used when
allocating 'ref'
- Changed arguments to get_system_var() from LEX_CSTRING to LEX_CSTRING*
- Added THD as argument to create_select_for_variable(). Changed also char*
argument to LEX_CSTRING to avoid strlen() call.
- Change calls to append() to use LEX_CSTRING
- Added sql/mariadb.h file that should be included first by files in sql
directory, if sql_plugin.h is not used (sql_plugin.h adds SHOW variables
that must be done before my_global.h is included)
- Removed a lot of include my_global.h from include files
- Removed include's of some files that my_global.h automatically includes
- Removed duplicated include's of my_sys.h
- Replaced include my_config.h with my_global.h
IB: Fixes in logic when to do versioned or usual row updates. Now it is
able to do unversioned updates for versioned tables just by disabling
`TABLE_SHARE::versioned` flag.
SQL: DDL tracking for:
* RENAME TABLE, ALTER TABLE .. RENAME TO;
* DROP TABLE;
* data-modifying operations (f.ex. ALTER TABLE .. ADD/DROP COLUMN).
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)
otherwise we'd need to store sql_mode *per vcol*
(consider CREATE INDEX...) and how SHOW CREATE TABLE would
support that?
Additionally, get rid of vcol::expr_str, just to make sure
the string is always generated and never leaked in the
original form.
