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2491 commits

Author SHA1 Message Date
Monty
5b4c8469d5 Added CHECK_FIELD_EXPRESSION
This is needed for MDEV 13679 Enabled sequences to be used in DEFAULT

Added new option for count_cuted_fields: CHECK_FIELD_EXPRESSION
which is used to check if a DEFAULT expression is correct before
ALTER TABLE starts

Changed also all test:
  if (thd->count_cuted_fields)
  to
  if (thd->count_cuted_fields > CHECK_FIELD_EXPRESSION)
2017-12-22 14:56:58 +02:00
Marko Mäkelä
0436a0ff3c Merge bb-10.2-ext into 10.3 2017-12-19 17:28:22 +02:00
Marko Mäkelä
028e91f380 Merge 10.2 into bb-10.2-ext 2017-12-19 17:12:14 +02:00
Marko Mäkelä
8d70097c21 Merge 10.1 to 10.2
Follow-up fix to MDEV-14008: Let Field_double::val_uint() silently
return 0 on error
2017-12-19 16:48:28 +02:00
Marko Mäkelä
09c5bbf471 Merge 10.0 into 10.1 2017-12-18 20:05:50 +02:00
Alexander Barkov
c1e5fef05d MDEV-14008 Assertion failing: `!is_set() || (m_status == DA_OK_BULK && is_bulk_op()) 2017-12-18 11:25:38 +04:00
Sachin Setiya
84726906c9 MDEV-10177 Invisible Columns and Invisible Index
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
2017-12-15 02:41:52 +05:30
Marko Mäkelä
866ccc8890 Merge bb-10.2-ext into 10.3 2017-12-14 11:34:30 +02:00
Alexander Barkov
a53e087ea9 MDEV-14628 Wrong autoinc value assigned by LOAD XML in the NO_AUTO_VALUE_ON_ZERO mode
The fixes for these bugs:

Bug#27586 Wrong autoinc value assigned by LOAD DATA in the NO_AUTO_VALUE_ON_ZERO mode
Bug#22372 Disable spatial key, load data, enable spatial key, crashes table

fixed only LOAD DATA INFILE, but did not fix LOAD XML INFILE.

This patch does for LOAD XML FILE what patches for Bug#27586 and Bug#22372
earlier did for LOAD DATA INFILE.

1. Fixing the auto_increment problem:
   a. table->auto_increment_field_not_null is not set to TRUE
      anymore when a column does not have a corresponding XML tag.
   b. Adding "table->auto_increment_field_not_null= false"
      in the end of read_xml_field().
   These two changes resemble the patch for Bug#27586.

2. Fixing the GEOMETRY problem:
   The result for "reset()" was not tested for errors in read_xml_field(),
   which made it possible for empty string to sneak into a "GEOMETRY NOT NULL"
   column when this column does not have a corresponding XML tag with data.
   After this patch the result of reset() is tested and and an error is
   returned in such cases.
   This change effectively resembles the patch for Bug#22372

3. Spliting the code into a new virtual method Field::load_data_set_null().

   Rationale:
   a. To avoid duplicate code in read_sep_field() and read_xml_field():
      Changes #1 and #2 made the code handling NULL values for Field
      exactly the same in read_sep_field() and read_xml_field().

  b. To avoid tests for field_type(), which is not friendly to
     upcoming data type plugins.
     This change makes it possible for data type plugins
     to implement their own special way for handling NULL values in LOAD DATA
     by overriding Field_xxx::load_data_set_null(),
     like Field_geom and Field_timestamp do.
2017-12-13 13:22:45 +04:00
Alexander Barkov
835cbbcc7b Merge remote-tracking branch 'origin/bb-10.2-ext' into 10.3
TODO: enable MDEV-13049 optimization for 10.3
2017-10-30 20:47:39 +04:00
Alexander Barkov
003cb2f424 Merge remote-tracking branch 'origin/10.2' into bb-10.2-ext 2017-10-30 16:42:46 +04:00
Alexander Barkov
667e4b97aa MDEV-14212 Add Field_row for SP ROW variables 2017-10-30 09:24:39 +04:00
Sergei Golubchik
e0a1c745ec Merge branch '10.1' into 10.2 2017-10-24 14:53:18 +02:00
Sergei Golubchik
9d2e2d7533 Merge branch '10.0' into 10.1 2017-10-22 13:03:41 +02:00
Sergei Golubchik
da4503e956 Merge branch '5.5' into 10.0 2017-10-18 15:14:39 +02:00
Alexander Barkov
30e7d6709f Merge remote-tracking branch 'origin/10.2' into bb-10.2-ext 2017-10-18 14:11:55 +04:00
Sergei Golubchik
df5f25fa7a Merge branch 'mysql/5.5' into 5.5 2017-10-17 10:18:17 +02:00
Sergei Golubchik
d76f5774fe MDEV-13459 Warnings, when compiling with gcc-7.x
mostly caused by -Wimplicit-fallthrough
2017-10-17 07:37:39 +02:00
Alexander Barkov
3062445a64 MDEV-14038 ALTER TABLE does not exit on error with InnoDB + bad default function
Changing Field::set_default from void to int.
It now uses the same return value notation with Field::store*()
and Item::save_in_field().
2017-10-11 18:13:44 +04:00
Alexander Barkov
a659291e85 MDEV-11586 UNION of FLOAT type results in erroneous precision
Fixing the asymmetry in the array field_types_merge_rules[][]
which caused data loss when mixing FLOAT + BIGINT in UNIONs
or hybrid functions:

1. FLOAT  + INT    = DOUBLE
2. FLOAT  + BIGINT = FLOAT
3. INT    + FLOAT  = DOUBLE
4. BIGINT + FLOAT  = DOUBLE

Now FLOAT + BIGINT (as in #2) also produces DOUBLE, like the cases #1,#3,#4 do.
2017-10-06 13:29:29 +04:00
Marko Mäkelä
2c1067166d Merge bb-10.2-ext into 10.3 2017-10-04 08:24:06 +03:00
Alexander Barkov
8ae8cd6348 Merge remote-tracking branch 'origin/10.2' into bb-10.2-ext 2017-10-02 22:35:13 +04:00
Vladislav Vaintroub
7354dc6773 MDEV-13384 - misc Windows warnings fixed 2017-09-28 17:20:46 +00:00
Vladislav Vaintroub
eba44874ca MDEV-13844 : Fix Windows warnings. Fix DBUG_PRINT.
- 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.
2017-09-28 17:20:46 +00:00
Marko Mäkelä
4a32e2395e Merge bb-10.2-ext into 10.3 2017-09-25 22:05:56 +03:00
Sergei Golubchik
1320ad5b92 Merge branch '10.2' into bb-10.2-ext 2017-09-23 20:22:30 +02:00
Sergei Golubchik
68d1a598bc bugfix: copy timestamps correctly in INSERT...SELECT
Implement Field_timestamp::save_in_field(timestamp_field)
that stores timestamp values without converting them to MYSQL_TIME
and back, because this conversion is lossy around DST change time.
This fixes main.old-mode test.

This is 10.2 version of f8a800bec8
2017-09-22 14:01:26 +02:00
Sergei Golubchik
bc4409ab4e MDEV-13868 cannot insert 1288481126 in a timestamp column in Europe/Moscow
make insert NULL into a timestamp mark the field as having an
explicit value. So that the field won't be assigned the value
again in TABLE::update_default_field()

make Item_func_now_local::save_in_field(timestamp_field) not to go
through MYSQL_TIME - this conversion is lossy around DST change times.
This fixes inserting a default value into a timestamp field.
2017-09-22 13:58:00 +02:00
Sergei Golubchik
f8a800bec8 bugfix: copy timestamps correctly in INSERT...SELECT
don't do it via MYSQL_TIME, that conversion is lossy
around DST change dates.
2017-09-21 22:03:28 +02:00
Sergey Vojtovich
fdc4779235 MDEV-11371 - column compression
Storage engine independent support for column compression.

TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT,
VARCHAR and VARBINARY columns can be compressed.

New COMPRESSED column attribute added:
COMPRESSED[=<compression_method>]

System variables added:
column_compression_threshold
column_compression_zlib_level
column_compression_zlib_strategy
column_compression_zlib_wrap

Status variables added:
Column_compressions
Column_decompressions

Limitations:
- the only supported method currently is zlib
- CSV storage engine stores data uncompressed on-disk even if COMPRESSED
  attribute is present
- it is not possible to create indexes over compressed columns.
2017-08-31 15:44:17 +04:00
Sergey Vojtovich
dd4e9cdded Get rid of Field::do_save_field_metadata()
It doesn't serve any purpose, but generates extra virtual function call.
2017-08-31 15:03:12 +04:00
Sergei Golubchik
a6e215f221 Fix compilation warnings in plugins
* update cracklib_password_check to match the new prototype
* cannot use __attribute__((format)) for my_snprintf, because
  we support format extensions that the compiler doesn't know about.
2017-08-24 01:05:48 +02:00
Michael Widenius
4aaa38d26e Enusure that my_global.h is included first
- 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
2017-08-24 01:05:44 +02:00
Tor Didriksen
ebd96c3149 Bug#19875294 ASSERTION `SRC' FAILED IN MY_STRNXFRM_UNICODE (SIG 6 -STRINGS/CTYPE-UTF8.C:5151)
Backport from 5.7 to 5.5 Field_set::val_str()
should return String("", 0, cs) rather than String(NULL, 0, cs)
2017-08-23 07:32:49 +02:00
Alexander Barkov
4937474f86 MDEV-13414 Fix the SP code to avoid excessive use of strlen 2017-07-31 17:34:59 +04:00
Sergei Golubchik
3ef5596505 MDEV-13175 Adding a new enum value at the end of a list triggers a table rebuild
Backport of 7e29f2d64f from 10.1.

Create_field does not set BINARY_FLAG, so the check didn't work at all.
Also, character sets were already compared, so this check would've been
redundant (if it would've worked).
2017-07-20 20:13:28 +02:00
Marko Mäkelä
70505dd45b Merge 10.1 into 10.2 2017-05-22 09:46:51 +03:00
Alexander Barkov
5b034f1cf8 MDEV-12833 Split Column_definition::create_length_to_internal_length() to virtual methods in Type_handler 2017-05-17 18:07:20 +04:00
Alexander Barkov
fba7fbbc5c MDEV-9397 Split field.cc:calc_pack_length() into virtual methods in Type_handler
- Adding new virtual methods in Type_handler:
  * Column_definition_prepare_stage1()
  * Column_definition_prepare_stage2()
  * calc_pack_length()

- Using new methods to remove type specific code in:
  * Global function calc_pack_length()
  * Column_definition::prepare_create_field()
  * The loop body mysql_prepare_create_table()
  * Column_definition::sp_prepare_create_field()
2017-05-17 12:21:39 +04:00
Marko Mäkelä
71cd205956 Silence bogus GCC 7 warnings -Wimplicit-fallthrough
Do not silence uncertain cases, or fix any bugs.

The only functional change should be that ha_federated::extra()
is not calling DBUG_PRINT to report an unhandled case for
HA_EXTRA_PREPARE_FOR_DROP.
2017-05-17 08:27:04 +03:00
Marko Mäkelä
7972da8aa1 Silence bogus GCC 7 warnings -Wimplicit-fallthrough
Do not silence uncertain cases, or fix any bugs.

The only functional change should be that ha_federated::extra()
is not calling DBUG_PRINT to report an unhandled case for
HA_EXTRA_PREPARE_FOR_DROP.
2017-05-17 08:07:02 +03:00
Alexander Barkov
f1b729d352 MDEV-9188 Split Column_definition::check() into virtual methods in Type_handler 2017-05-16 14:29:51 +04:00
Alexander Barkov
533506b4ed MDEV-12777 Change Lex_field_type_st::m_type from enum_field_types to Type_handler pointer 2017-05-10 18:14:08 +04:00
Alexander Barkov
cc694792c9 MDEV-12717 Change Item_equal to operate Type_handler rather than Item_result 2017-05-07 01:02:37 +04:00
Alexander Barkov
aacb4d57ca MDEV-12695 Add Column_definition::type_handler() 2017-05-05 07:00:18 +04:00
Alexander Barkov
441349aa06 MDEV-12588 Add Type_handler::type_handler_for_tmp_table() and Type_handler::type_handler_for_union()
1. Implementing the task according to the description:

a. Adding Type_handler::type_handler_for_tmp_table().
b. Adding Type_handler::type_handler_for_union_table.
c. Adding helper methods Type_handler::varstring_type_handler(const Item*),
   Type_handler::blob_type_handler(const Item*)
d. Removing Item::make_string_field() and
   Item_func_group_concat::make_string_field().
   They are not needed any more.
e. Simplifying Item::tmp_table_field_from_field_type() to just two lines.
f. Renaming Item_type_holder::make_field_by_type() and implementing
   virtual Item_type_holder::create_tmp_field() instead.
   The new implementation is also as simple as two lines.
g. Adding a new virtual method Type_all_attributes::get_typelib(),
   to access to TYPELIB definitions for ENUM and SET columns.
h. Simplifying the code branch for TIME_RESULT, DECIMAL_RESULT, STRING_RESULT
   in Item::create_tmp_field(). It's now just one line.
i. Implementing Type_handler_enum::make_table_field() and
   Type_handler_set::make_table_field().

2. Code simplification in Field_str constructor calls.

a. Changing the "CHARSET_INFO *cs" argument in constuctors for Field_str
   and its descendants to "const DTCollation &collation". This is to
   avoid two step initialization:
   - setting Field_str::derivation and Field_str::repertoire to the
     default values first
   - then resetting them using:
     set_derivation(item->derivation, item->repertoire).

b. Removing Field::set_derivation()

c. Adding a new constructor DTCollation(CHARSET_INFO *cs),
   for the old code compatibility.

3. Changes in test results

As a side effect some test results have changed, because
in the old version Item::make_string_field() converted
TINYBLOB to VARCHAR(255). Now TINYBLOB is preserved.

a. sp-row.result
   This query:
     CREATE TABLE t1 AS SELECT tinyblob_sp_variable;
   Now preserves TINYBLOB as the data type.
   Before the patch a VARCHAR(255) was created.

b. gis-debug.result
   This is a debug test, to make sure that + and - operators
   are commutative and non-commutative correspondingly.
   The exact data type is not really important.
   (But anyway, it now chooses a better data type that fits the result)
2017-04-27 14:37:27 +04:00
Alexander Barkov
b445c1ebb5 Fixing compilation failure on Windows: moving references to type_handler_xxx from field.h to field.cc 2017-04-26 10:52:18 +04:00
Alexander Barkov
2fd635409d MDEV-12426 Add Field::type_handler() + MDEV-12432
This is a joint patch for:

- MDEV-12426 Add Field::type_handler()
- MDEV-12432 Range optimizer for ENUM and SET does not return "Impossible WHERE" in some case

With the new type handler approach being added to Field, it was easier to fix
MDEV-12432 rather than to reproduce the old ENUM/SET behavior.

The patch does the following:

1. Adds Field::type_handler(), according to the task description.

2. Fixes the asymmetry between Fields and Items of ENUM and SET field types.
   Field_enum::cmp_type() returned INT_RESULT
   Item*::cmp_type() returned STRING_RESULT for ENUM and SET expressions

This asymmetry was originally done for easier coding in the optimizer sources.
However, in 10.1 we moved a lot of code to methods of the class Field:
- test_if_equality_guarantees_uniqueness()
- can_be_substituted_to_equal_item()
- get_equal_const_item()
- can_optimize_keypart_ref()
- can_optimize_hash_join()
- can_optimize_group_min_max()
- can_optimize_range()
- can_optimize_outer_join_table_elimination()

As of 10.2 only a few lines of the code in opt_range.cc, field.cc and field.h
still relayed on the fact that Field_enum::cmp_type() returns INT_RESULT:
- Some asserts in field.cc
- Field_year::get_copy_func()
- Item_func_like::get_mm_leaf()
- Item_bool_func::get_mm_leaf()
These lines have been fixed.

3. Item_bool_func::get_mm_leaf() did not work well for ENUM/SET,
see MDEV-12432. So the ENUM/SET code was rewritten, and the relevant
code in Field_enum::store() and Field_set::store() was fixed to
properly return errors to the caller.

4. The result of Field_decimal::result_type() was changed from REAL_RESULT
to DECIMAL_RESULT. Data type aggregation (e.g. in COALESCE()) is now more
precise for old DECIMAL, because Item::decimal_precision() now goes through
the DECIMAL_RESULT branch. Earlier it went through the REAL_RESULT branch.
2017-04-25 14:22:07 +04:00
Alexander Barkov
5f1544fef3 A cleanup for MDEV-9217 Split Item::tmp_table_field_from_field_type() into virtual methods in Type_handler
Fixing that the server tried to create the old decimal for:

  CREATE TABLE t2 AS SELECT old_decimal_field FROM t1
               UNION SELECT bigint_field FROM t1;

  CREATE TABLE t2 AS SELECT old_decimal_field FROM t1
               UNION SELECT mediumint_field FROM t1;

  CREATE TABLE t2 AS SELECT year FROM t1
               UNION SELECT old_decimal_field FROM t1;

  CREATE TABLE t2 AS SELCT COALESCE(old_decimal_field) FROM t1;

Solution:

1. field_types_merge_rules[][] had three MYSQL_TYPE_DECIMAL remainders.
   Fixing to MYSQL_TYPE_NEWDECIMAL, like it is done for all other type pairs.
   This fixes the above queries with UNION.

2. Convert MYSQL_TYPE_DECIMAL to MYSQL_TYPE_NEWDECIMAL in
   Item::tmp_table_field_from_field_type().
   This fixed the above query with COALESCE.

3. Adding "new Field_decimal" into Type_handler_olddecimal::make_table_field().
   In case if something goes wrong it will crash on assert only in debug builds,
   while create the old decimal in release.
   Note, this "new Field_decimal" will be needed later anyway,
   when we reuse Type_handler::make_table_field() in make_field() in field.cc.
2017-04-24 16:08:28 +04:00
Alexander Barkov
791374354c MDEV-9217 Split Item::tmp_table_field_from_field_type() into virtual methods in Type_handler
- Adding Type_handler::make_table_field() and moving pieces of the code
  from Item::tmp_table_field_from_field_type() to virtual implementations
  for various type handlers.

- Adding a new Type_all_attributes, to access to Item's extended
  attributes, such as decimal_precision() and geometry_type().

- Adding a new class Record_addr, to pass record related information
  to Type_handler methods (ptr, null_ptr and null_bit) as a single structure.
  Note, later it will possibly be extended for BIT-alike field purposes,
  by adding new members (bit_ptr_arg, bit_ofs_arg).

- Moving the code from Field_new_decimal::create_from_item()
  to Type_handler_newdecimal::make_table_field().

- Removing Field_new_decimal() and Field_geom() helper constructor
  variants that were used for temporary field creation.

- Adding Item_field::type_handler(), Field::type_handler() and
  Field_blob::type_handler() to return correct type handlers for
  blob variants, according to Field_blob::packlength.

- Adding Type_handler_blob_common, as a common parent for
  Type_handler_tiny_blob, Type_handler_blob, Type_handler_medium_blob
  and Type_handler_long_blob.

- Implementing Type_handler_blob_common::Item_hybrid_func_fix_attributes().

  It's needed for cases when TEXT variants of different character sets are mixed
  in LEAST, GREATEST, CASE and its abreviations (IF, IFNULL, COALESCE), e.g.:
      CREATE TABLE t1 (
        a TINYTEXT CHARACTER SET latin1,
        b TINYTEXT CHARACTER SET utf8
      );
      CREATE TABLE t2 AS SELECT COALESCE(a,b) FROM t1;
  Type handler aggregation returns TINYTEXT as a common data type
  for the two columns. But as conversion from latin1 to utf8
  happens for "a", the maximum possible length of "a" grows from 255 to 255*3.
  Type_handler_blob_common::Item_hybrid_func_fix_attributes() makes sure
  to update the blob type handler according to max_length.

- Adding Type_handler::blob_type_handler(uint max_octet_length).

- Adding a few m_type_aggregator_for_result.add() pairs, because
  now Item_xxx::type_handler() can return pointers to type_handler_tiny_blob,
  type_handler_blob, type_handler_medium_blob, type_handler_long_blob.
  Before the patch only type_handler_blob was possible result of type_handler().

- Making type_handler_tiny_blob, type_handler_blob, type_handler_medium_blob,
  type_handler_long_blob public.

- Removing the condition in Item_sum_avg::create_tmp_field()
  checking Item_sum_avg::result_type() against DECIMAL_RESULT.
  Now both REAL_RESULT and DECIMAL_RESULT are symmetrically handled
  by tmp_table_field_from_field_type().

- Removing Item_geometry_func::create_field_for_create_select(),
  as the inherited version perfectly works.

- Fixing Item_func_as_wkb::field_type() to return MYSQL_TYPE_LONG_BLOB
  rather than MYSQL_TYPE_BLOB. It's needed to make sure that
  tmp_table_field_from_field_type() creates a LONGBLOB field for AsWKB().

- Fixing Item_func_as_wkt::fix_length_and_dec() to set max_length to
  UINT32_MAX rather than MAX_BLOB_WIDTH, to make sure that
  tmp_table_field_from_field_type() creates a LONGTEXT field for AsWKT().

- Removing Item_func_set_user_var::create_field_for_create_select(),
  as the inherited version works fine.

- Adding Item_func_get_user_var::create_field_for_create_select() to
  make sure that "CREATE TABLE t1 AS SELECT @string_user variable"
  always creates a field of LONGTEXT/LONGBLOB type.

- Item_func_ifnull::create_field_for_create_select()
  behavior has changed. Before the patch it passed set_blob_packflag=false,
  which meant to create LONGBLOB for all blob variants.
  Now it takes into account max_length, which gives better column
  data types for:
    CREATE TABLE t2 AS SELECT IFNULL(blob_column1, blob_column2) FROM t1;

- Fixing Item_func_nullif::fix_length_and_dec() to use
  set_handler(args[2]->type_handler()) instead of
  set_handler_by_field_type(args[2]->field_type()).
  This is needed to distinguish between BLOB variants.

- Implementing Item_blob::type_handler(), to make sure to create
  proper BLOB field variant, according to max_length, for queries like:
    CREATE TABLE t1 AS
      SELECT some_blob_field FROM INFORMATION_SCHEMA.SOME_TABLE;

- Fixing Item_field::real_type_handler() to make sure that
  the code aggregating fields for UNION gets a proper BLOB
  variant type handler from fields.

- Adding a special code into Item_type_holder::make_field_by_type(),
  to make sure that after aggregating field types it also properly
  takes into account max_length when mixing TEXT variants of different
  character sets and chooses a proper TEXT variant:
      CREATE TABLE t1 (
        a TINYTEXT CHARACTER SET latin1,
        b TINYTEXT CHARACTER SET utf8
      );
      CREATE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;

- Adding tests, for better coverage of IFNULL, NULLIF, UNION.

- The fact that tmp_table_field_from_field_type() now takes
  into account BLOB variants (instead of always creating LONGBLOB),
  tests results for WEIGHT_STRING() and NULLIF() and UNION
  have become more precise.
2017-04-24 12:09:25 +04:00