Commit graph

177 commits

Author SHA1 Message Date
Evgeny Potemkin
726e83907c Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
MySQL manual describes values of the YEAR(2) field type as follows:
values 00 - 69 mean 2000 - 2069 years and values 70 - 99 mean 1970 - 1999
years. MIN/MAX and comparison functions was comparing them as int values
thus producing wrong result.

Now the Arg_comparator class is extended with compare_year function which
performs correct comparison of the YEAR type.
The Item_sum_hybrid class now uses Item_cache and Arg_comparator objects to
correctly calculate its value.
To allow Arg_comparator to use func_name() function for Item_func and Item_sum
objects the func_name declaration is moved to the Item_result_field class.
A helper function is_owner_equal_func is added to the Arg_comparator class.
It checks whether the Arg_comparator object owner is the <=> function or not.
A helper function setup is added to the Item_sum_hybrid class. It sets up
cache item and comparator.
2009-11-17 17:06:46 +03:00
Georgi Kodinov
b5f152dcd8 Bug#34773: query with explain extended and derived table / other table
crashes server

When creating temporary table that contains aggregate functions a 
non-reversible source transformation was performed to redirect aggregate
function arguments towards temporary table columns.
This caused EXPLAIN EXTENDED to fail because it was trying to resolve
references to the (freed) temporary table.
Fixed by preserving the original aggregate function arguments and
using them (instead of the transformed ones) for EXPLAIN EXTENDED.
2008-10-06 17:17:25 +03:00
evgen@moonbone.local
8fe48b6875 Merge moonbone.local:/work/27219-5.0-opt-mysql
into  moonbone.local:/work/27219-bug-5.1
2008-03-28 18:09:14 +03:00
evgen@moonbone.local
21c6145a6e Bug#27219: Aggregate functions in ORDER BY.
Mixing aggregate functions and non-grouping columns is not allowed in the
ONLY_FULL_GROUP_BY mode. However in some cases the error wasn't thrown because
of insufficient check.

In order to check more thoroughly the new algorithm employs a list of outer
fields used in a sum function and a SELECT_LEX::full_group_by_flag.
Each non-outer field checked to find out whether it's aggregated or not and
the current select is marked accordingly.
All outer fields that are used under an aggregate function are added to the
Item_sum::outer_fields list and later checked by the Item_sum::check_sum_func
function.
2008-03-27 19:49:32 +03:00
anozdrin/alik@quad.
340906f46d Fix for Bug#30217: Views: changes in metadata behaviour
between 5.0 and 5.1.
  
The problem was that in the patch for Bug#11986 it was decided
to store original query in UTF8 encoding for the INFORMATION_SCHEMA.
This approach however turned out to be quite difficult to implement
properly. The main problem is to preserve the same IS-output after
dump/restore.
  
So, the fix is to rollback to the previous functionality, but also
to fix it to support multi-character-set-queries properly. The idea
is to generate INFORMATION_SCHEMA-query from the item-tree after
parsing view declaration. The IS-query should:
  - be completely in UTF8;
  - not contain character set introducers.
  
For more information, see WL4052.
2008-02-22 13:30:33 +03:00
mhansson/martin@linux-st28.site
8e8ba8e825 Merge linux-st28.site:/home/martin/mysql/src/bug32798-united/my50-bug32798-united
into  linux-st28.site:/home/martin/mysql/src/bug32798-united/my51-bug32798-united
2007-12-14 12:40:39 +01:00
mhansson/martin@linux-st28.site
cdeecc5154 Bug#32798: DISTINCT in GROUP_CONCAT clause fails when ordering by a column
with null values

For queries containing GROUP_CONCAT(DISTINCT fields ORDER BY fields), there 
was a limitation that the DISTINCT fields had to be the same as ORDER BY 
fields, owing to the fact that one single sorted tree was used for keeping 
track of tuples, ordering and uniqueness. Fixed by introducing a second 
structure to handle uniqueness so that the original structure has only to 
order the result.
2007-12-14 12:24:20 +01:00
igor@olga.mysql.com
259fdbf9ca Merge olga.mysql.com:/home/igor/mysql-5.0-opt
into  olga.mysql.com:/home/igor/dev-opt/mysql-5.1-opt
2007-06-30 20:49:28 -07:00
gkodinov/kgeorge@magare.gmz
38172240e3 Bug#27333: subquery grouped for aggregate of outer
query / no aggregate of subquery
 The optimizer counts the aggregate functions that 
 appear as top level expressions (in all_fields) in 
 the current subquery. Later it makes a list of these
 that it uses to actually execute the aggregates in
 end_send_group().
 That count is used in several places as a flag whether
 there are aggregates functions.
 While collecting the above info it must not consider
 aggregates that are not aggregated in the current 
 context. It must treat them as normal expressions 
 instead. Not doing that leads to incorrect data about
 the query, e.g. running a query that actually has no
 aggregate functions as if it has some (and hence is
 expected to return only one row).
 Fixed by ignoring the aggregates that are not aggregated
 in the current context. 
 One other smaller omission discovered and fixed in the 
 process : the place of aggregation was not calculated for
 user defined functions. Fixed by calling 
 Item_sum::init_sum_func_check() and 
 Item_sum::check_sum_func() as it's done for the rest of 
 the aggregate functions.
2007-06-29 10:39:17 +03:00
monty@mysql.com/narttu.mysql.fi
088e2395f1 WL#3817: Simplify string / memory area types and make things more consistent (first part)
The following type conversions was done:

- Changed byte to uchar
- Changed gptr to uchar*
- Change my_string to char *
- Change my_size_t to size_t
- Change size_s to size_t

Removed declaration of byte, gptr, my_string, my_size_t and size_s. 

Following function parameter changes was done:
- All string functions in mysys/strings was changed to use size_t
  instead of uint for string lengths.
- All read()/write() functions changed to use size_t (including vio).
- All protocoll functions changed to use size_t instead of uint
- Functions that used a pointer to a string length was changed to use size_t*
- Changed malloc(), free() and related functions from using gptr to use void *
  as this requires fewer casts in the code and is more in line with how the
  standard functions work.
- Added extra length argument to dirname_part() to return the length of the
  created string.
- Changed (at least) following functions to take uchar* as argument:
  - db_dump()
  - my_net_write()
  - net_write_command()
  - net_store_data()
  - DBUG_DUMP()
  - decimal2bin() & bin2decimal()
- Changed my_compress() and my_uncompress() to use size_t. Changed one
  argument to my_uncompress() from a pointer to a value as we only return
  one value (makes function easier to use).
- Changed type of 'pack_data' argument to packfrm() to avoid casts.
- Changed in readfrm() and writefrom(), ha_discover and handler::discover()
  the type for argument 'frmdata' to uchar** to avoid casts.
- Changed most Field functions to use uchar* instead of char* (reduced a lot of
  casts).
- Changed field->val_xxx(xxx, new_ptr) to take const pointers.

Other changes:
- Removed a lot of not needed casts
- Added a few new cast required by other changes
- Added some cast to my_multi_malloc() arguments for safety (as string lengths
  needs to be uint, not size_t).
- Fixed all calls to hash-get-key functions to use size_t*. (Needed to be done
  explicitely as this conflict was often hided by casting the function to
  hash_get_key).
- Changed some buffers to memory regions to uchar* to avoid casts.
- Changed some string lengths from uint to size_t.
- Changed field->ptr to be uchar* instead of char*. This allowed us to
  get rid of a lot of casts.
- Some changes from true -> TRUE, false -> FALSE, unsigned char -> uchar
- Include zlib.h in some files as we needed declaration of crc32()
- Changed MY_FILE_ERROR to be (size_t) -1.
- Changed many variables to hold the result of my_read() / my_write() to be
  size_t. This was needed to properly detect errors (which are
  returned as (size_t) -1).
- Removed some very old VMS code
- Changed packfrm()/unpackfrm() to not be depending on uint size
  (portability fix)
- Removed windows specific code to restore cursor position as this
  causes slowdown on windows and we should not mix read() and pread()
  calls anyway as this is not thread safe. Updated function comment to
  reflect this. Changed function that depended on original behavior of
  my_pwrite() to itself restore the cursor position (one such case).
- Added some missing checking of return value of malloc().
- Changed definition of MOD_PAD_CHAR_TO_FULL_LENGTH to avoid 'long' overflow.
- Changed type of table_def::m_size from my_size_t to ulong to reflect that
  m_size is the number of elements in the array, not a string/memory
  length.
- Moved THD::max_row_length() to table.cc (as it's not depending on THD).
  Inlined max_row_length_blob() into this function.
- More function comments
- Fixed some compiler warnings when compiled without partitions.
- Removed setting of LEX_STRING() arguments in declaration (portability fix).
- Some trivial indentation/variable name changes.
- Some trivial code simplifications:
  - Replaced some calls to alloc_root + memcpy to use
    strmake_root()/strdup_root().
  - Changed some calls from memdup() to strmake() (Safety fix)
  - Simpler loops in client-simple.c
2007-05-10 12:59:39 +03:00
gkodinov/kgeorge@magare.gmz
bd3a0ce1d9 Merge magare.gmz:/home/kgeorge/mysql/work/WL3527-5.0-opt
into  magare.gmz:/home/kgeorge/mysql/work/WL3527-5.1-opt
2007-03-26 17:03:57 +03:00
igor@olga.mysql.com
8f9178e857 Fixed bug #27229: crash when a set function aggregated in outer
context was used as an argument of GROUP_CONCAT.
Ensured correct setting of the depended_from field in references
generated for set functions aggregated in outer selects.
A wrong value of this field resulted in wrong maps returned by 
used_tables() for these references.
Made sure that a temporary table field is added for any set function
aggregated in outer context when creation of a temporary table is 
needed to execute the inner subquery.
2007-03-22 14:48:03 -07:00
holyfoot/hf@hfmain.(none)
d24fb40374 Merge mysql.com:/home/hf/work/mrg/mysql-5.0-opt
into  mysql.com:/home/hf/work/mrg/mysql-5.1-opt
2007-03-22 11:43:23 +04:00
gkodinov/kgeorge@macbook.local
28962a76a3 Bug #24484:
To correctly decide which predicates can be evaluated with a given table
the optimizer must know the exact set of tables that a predicate depends 
on. If that mask is too wide (refer to non-existing tables) the optimizer
can erroneously skip a predicate.
One such case of wrong table usage mask were the aggregate functions.
The have a all-1 mask (meaning depend on all tables, including non-existent
ones).
Fixed by making a real used_tables mask for the aggregates. The mask is
constructed in the following way :
1. OR the table dependency masks of all the arguments of the aggregate.
2. If all the arguments of the function are from the local name resolution 
  context and it is evaluated in the same name resolution
  context where it is referenced all the tables from that name resolution 
  context are OR-ed to the dependency mask. This is to denote that an
  aggregate function depends on the number of rows it processes.
3. Handle correctly the case of an aggregate function optimization (such that
  the aggregate function can be pre-calculated and made a constant).

Made sure that an aggregate function is never a constant (unless subject of a 
specific optimization and pre-calculation).  

One other flaw was revealed and fixed in the process : references were 
not calling the recalculation method for used_tables of their targets.
2007-03-20 19:46:02 +02:00
tsmith@siva.hindu.god
cc7afe2494 Merge siva.hindu.god:/home/tsmith/m/bk/mrg-jan17/51
into  siva.hindu.god:/home/tsmith/m/bk/mrg-jan17/maint/51
2007-01-18 08:30:35 -07:00
malff/marcsql@weblab.(none)
b73101af15 Merge malff@bk-internal.mysql.com:/home/bk/mysql-5.1-runtime
into  weblab.(none):/home/marcsql/TREE/mysql-5.1-22687
2007-01-12 08:11:52 -07:00
malff/marcsql@weblab.(none)
9655f5fb03 Bug#22687 (Functions UNIQUE_USERS, GROUP_UNIQUE_USERS)
According to some internal communication, these two functions are place
holders for future enhancements. Because they use a variable number of
parameters, the implementation defined a reserved keyword for them in the
parser grammar.

Unfortunately, doing so creates a bug similar to Bug 21114 reported for the
function FORMAT.

In the 5.1 code base, due to improvements in the code implemented with bug
21114, having a reserved keyword for functions with a variable number of
arguments is not needed any more by the implementation.

As a result, this fix removes the place-holder implementation, and removes
the unnecessary reserved keywords. Should the functions UNIQUE_USERS and
GROUP_UNIQUE_USERS be finally implemented in a later release, the
implementation should sub class Create_native_func in sql/item_create.cc.
For example, see the class Create_func_concat.
2007-01-11 14:58:05 -07:00
cmiller@zippy.cornsilk.net
896e2623eb Merge bk-internal.mysql.com:/home/bk/mysql-5.0
into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-5.0-maint
2007-01-11 09:43:44 -05:00
cmiller@zippy.cornsilk.net
a16eaf3301 Merge bk-internal.mysql.com:/home/bk/mysql-5.1
into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-5.1-maint-greener
2007-01-07 09:31:49 -05:00
kent@kent-amd64.(none)
58763e383e Merge mysql.com:/home/kent/bk/main/mysql-5.0
into  mysql.com:/home/kent/bk/main/mysql-5.1
2006-12-31 01:32:21 +01:00
kent@mysql.com/kent-amd64.(none)
6523aca729 my_strtoll10-x86.s:
Corrected spelling in copyright text
Makefile.am:
  Don't update the files from BitKeeper
Many files:
  Removed "MySQL Finland AB & TCX DataKonsult AB" from copyright header
  Adjusted year(s) in copyright header 
Many files:
  Added GPL copyright text
Removed files:
  Docs/Support/colspec-fix.pl
  Docs/Support/docbook-fixup.pl
  Docs/Support/docbook-prefix.pl
  Docs/Support/docbook-split
  Docs/Support/make-docbook
  Docs/Support/make-makefile
  Docs/Support/test-make-manual
  Docs/Support/test-make-manual-de
  Docs/Support/xwf
2006-12-31 01:02:27 +01:00
tsmith/tim@siva.hindu.god
682596d7ce Merge siva.hindu.god:/usr/home/tim/m/bk/g50
into  siva.hindu.god:/usr/home/tim/m/bk/50
2006-12-26 22:28:28 -07:00
tsmith/tim@siva.hindu.god
0cb9cee7f4 Merge siva.hindu.god:/usr/home/tim/m/bk/g51
into  siva.hindu.god:/usr/home/tim/m/bk/tmp/mrg51-dec26
2006-12-26 16:49:10 -07:00
kent@kent-amd64.(none)
be15e3bc15 Merge mysql.com:/home/kent/bk/main/mysql-5.0
into  mysql.com:/home/kent/bk/main/mysql-5.1
2006-12-23 20:20:40 +01:00
kent@mysql.com/kent-amd64.(none)
226a5c833f Many files:
Changed header to GPL version 2 only
2006-12-23 20:17:15 +01:00
cmiller@zippy.cornsilk.net
fa6f173bf8 Merge zippy.cornsilk.net:/home/cmiller/work/mysql/bug22555/my51-bug22555
into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-5.1-maint
2006-12-22 16:05:59 -05:00
cmiller@zippy.cornsilk.net
8ffe6fb522 Merge zippy.cornsilk.net:/home/cmiller/work/mysql/bug22555/my50-bug22555
into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-5.0-maint
2006-12-22 16:02:54 -05:00
cmiller@zippy.cornsilk.net
83355bfb81 Merge zippy.cornsilk.net:/home/cmiller/work/mysql/bug22555/my50-bug22555
into  zippy.cornsilk.net:/home/cmiller/work/mysql/bug22555/my51-bug22555
2006-12-22 15:59:10 -05:00
cmiller@zippy.cornsilk.net
50726b2322 Bug#22555: STDDEV yields positive result for groups with only one row
When only one row was present, the subtraction of nearly the same number 
resulted in catastropic cancellation, introducing an error in the 
VARIANCE calculation near 1e-15.  That was sqrt()ed to get STDDEV, the 
error was escallated to near 1e-8.  

The simple fix of testing for a row count of 1 and forcing that to yield 
0.0 is insufficient, as two rows of the same value should also have a
variance of 0.0, yet the error would be about the same.

So, this patch changes the formula that computes the VARIANCE to be one
that is not subject to catastrophic cancellation.

In addition, it now uses only (faster-than-decimal) floating point numbers
to calculate, and renders that to other types on demand.
2006-12-22 15:37:37 -05:00
baker@bk-internal.mysql.com
dbe5f0acc5 Merge bk-internal.mysql.com:/data0/bk/mysql-5.1
into  bk-internal.mysql.com:/data0/bk/mysql-5.1-arch
2006-12-03 21:19:35 +01:00
brian@zim.(none)
31d67280f7 This finishes the work (someone) started to remove FIELD_ types and use the Enum MYSQL types. The second part to this is to actually deprecate the FIELD defines in mysql_com.h 2006-12-01 17:26:52 -08:00
gkodinov@dl145s.mysql.com
b58b551810 Merge dl145s.mysql.com:/data0/bk/team_tree_merge/mysql-5.0-opt
into  dl145s.mysql.com:/data0/bk/team_tree_merge/MERGE2/mysql-5.1-opt
2006-11-29 11:48:44 +01:00
gkodinov/kgeorge@rakia.gmz
fb41ec6f22 Merge gkodinov@bk-internal.mysql.com:/home/bk/mysql-5.0-opt
into  rakia.gmz:/home/kgeorge/mysql/autopush/B11927-5.0-opt
2006-11-28 15:47:53 +02:00
gkodinov/kgeorge@macbook.gmz
42cd956752 BUG#11927: Warnings shown for CAST( chr as signed) but not (chr + 0)
When implicitly converting string fields to numbers the 
 string-to-number conversion error was not sent to the client.
 Added code to send the conversion error as warning.
 
 We also need to prevent generation of warnings from the places
 where val_xxx() methods are called for the sole purpose of updating
 the Item::null_value flag.
 To achieve that a special function is added (and called) : 
 update_null_value(). This function will set the no_errors flag and
 will call val_xxx(). The warning generation in Field_string::val_xxx()
 will use the flag when generating the conversion warnings.
2006-11-28 15:44:11 +02:00
holyfoot/hf@deer.(none)
7d190dd6b1 Merge bk@192.168.21.1:mysql-5.1-opt
into  mysql.com:/home/hf/work/mysql-5.1-mrg
2006-11-17 19:01:35 +04:00
holyfoot/hf@mysql.com/deer.(none)
e95e23b0f3 Merge bk@192.168.21.1:mysql-5.0-opt
into  mysql.com:/home/hf/work/mysql-5.0-0mrg
2006-11-17 10:30:16 +04:00
holyfoot/hf@deer.(none)
938ba3e11e Merge mysql.com:/home/hf/work/mysql-5.0.clean
into  mysql.com:/home/hf/work/mysql-5.1.clean
2006-11-08 19:09:39 +04:00
gkodinov/kgeorge@macbook.gmz
6cd1f7b2e5 Bug #23184: SELECT causes server crash
Item::val_xxx() may be called by the server several times at execute time 
 for a single query. Calls to val_xxx() may be very expensive and sometimes
 (count(distinct), sum(distinct), avg(distinct)) not possible.
 To avoid that problem the results of calculation for these aggregate 
 functions are cached so that val_xxx() methods just return the calculated 
 value for the second and subsequent calls.
2006-10-31 11:01:27 +02:00
kostja@bodhi.local
2fecf79536 Merge bodhi.local:/opt/local/work/mysql-5.0-runtime
into  bodhi.local:/opt/local/work/mysql-5.1-runtime-merge
2006-10-23 12:35:56 +04:00
kroki/tomash@moonlight.intranet
9fd2c86103 Fix for valgrind warning introduced by the fix for bug#21354:
(COUNT(*) = 1) not working in SELECT inside prepared statement.
Note: the warning was introduced in 5.0 and 5.1, 4.1 is OK with the
original fix.

The problem was that in 5.0 and 5.1 clear() for group functions may
access hybrid_type member, and this member is initialized in
fix_fields().

So we should not call clear() from item cleanup() methods, as cleanup()
may be called for unfixed items.
2006-10-18 15:20:34 +04:00
kroki/tomash@moonlight.intranet
f999aaa301 Merge moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.0-bug21354
into  moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.1-bug21354
2006-10-10 17:28:11 +04:00
kroki/tomash@moonlight.intranet
0d457976ea Merge moonlight.intranet:/home/tomash/src/mysql_ab/mysql-4.1-bug21354
into  moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.0-bug21354
2006-10-10 17:18:36 +04:00
kroki/tomash@moonlight.intranet
fbf6507cf7 BUG#21354: (COUNT(*) = 1) not working in SELECT inside prepared
statement.

The problem was that during statement re-execution if the result was
empty the old result could be returned for group functions.

The solution is to implement proper cleanup() method in group
functions.
2006-10-10 17:08:47 +04:00
kostja@bodhi.local
04c97488f9 Merge bodhi.local:/opt/local/work/tmp_merge
into  bodhi.local:/opt/local/work/mysql-5.1-runtime-merge
2006-08-12 21:06:51 +04:00
ramil/ram@mysql.com/myoffice.izhnet.ru
a810a2a437 Merge rkalimullin@bk-internal.mysql.com:/home/bk/mysql-5.0-maint
into  mysql.com:/usr/home/ram/work/5.0.b10966
2006-07-23 12:58:26 +05:00
monty@mysql.com
74cc73d461 This changeset is largely a handler cleanup changeset (WL#3281), but includes fixes and cleanups that was found necessary while testing the handler changes
Changes that requires code changes in other code of other storage engines.
(Note that all changes are very straightforward and one should find all issues
by compiling a --debug build and fixing all compiler errors and all
asserts in field.cc while running the test suite),

- New optional handler function introduced: reset()
  This is called after every DML statement to make it easy for a handler to
  statement specific cleanups.
  (The only case it's not called is if force the file to be closed)

- handler::extra(HA_EXTRA_RESET) is removed. Code that was there before
  should be moved to handler::reset()

- table->read_set contains a bitmap over all columns that are needed
  in the query.  read_row() and similar functions only needs to read these
  columns
- table->write_set contains a bitmap over all columns that will be updated
  in the query. write_row() and update_row() only needs to update these
  columns.
  The above bitmaps should now be up to date in all context
  (including ALTER TABLE, filesort()).

  The handler is informed of any changes to the bitmap after
  fix_fields() by calling the virtual function
  handler::column_bitmaps_signal(). If the handler does caching of
  these bitmaps (instead of using table->read_set, table->write_set),
  it should redo the caching in this code. as the signal() may be sent
  several times, it's probably best to set a variable in the signal
  and redo the caching on read_row() / write_row() if the variable was
  set.

- Removed the read_set and write_set bitmap objects from the handler class

- Removed all column bit handling functions from the handler class.
  (Now one instead uses the normal bitmap functions in my_bitmap.c instead
  of handler dedicated bitmap functions)

- field->query_id is removed. One should instead instead check
  table->read_set and table->write_set if a field is used in the query.

- handler::extra(HA_EXTRA_RETRIVE_ALL_COLS) and
  handler::extra(HA_EXTRA_RETRIEVE_PRIMARY_KEY) are removed. One should now
  instead use table->read_set to check for which columns to retrieve.

- If a handler needs to call Field->val() or Field->store() on columns
  that are not used in the query, one should install a temporary
  all-columns-used map while doing so. For this, we provide the following
  functions:

  my_bitmap_map *old_map= dbug_tmp_use_all_columns(table, table->read_set);
  field->val();
  dbug_tmp_restore_column_map(table->read_set, old_map);

  and similar for the write map:

  my_bitmap_map *old_map= dbug_tmp_use_all_columns(table, table->write_set);
  field->val();
  dbug_tmp_restore_column_map(table->write_set, old_map);

  If this is not done, you will sooner or later hit a DBUG_ASSERT
  in the field store() / val() functions.
  (For not DBUG binaries, the dbug_tmp_restore_column_map() and
  dbug_tmp_restore_column_map() are inline dummy functions and should
  be optimized away be the compiler).

- If one needs to temporary set the column map for all binaries (and not
  just to avoid the DBUG_ASSERT() in the Field::store() / Field::val()
  methods) one should use the functions tmp_use_all_columns() and
  tmp_restore_column_map() instead of the above dbug_ variants.

- All 'status' fields in the handler base class (like records,
  data_file_length etc) are now stored in a 'stats' struct. This makes
  it easier to know what status variables are provided by the base
  handler.  This requires some trivial variable names in the extra()
  function.

- New virtual function handler::records().  This is called to optimize
  COUNT(*) if (handler::table_flags() & HA_HAS_RECORDS()) is true.
  (stats.records is not supposed to be an exact value. It's only has to
  be 'reasonable enough' for the optimizer to be able to choose a good
  optimization path).

- Non virtual handler::init() function added for caching of virtual
  constants from engine.

- Removed has_transactions() virtual method. Now one should instead return
  HA_NO_TRANSACTIONS in table_flags() if the table handler DOES NOT support
  transactions.

- The 'xxxx_create_handler()' function now has a MEM_ROOT_root argument
  that is to be used with 'new handler_name()' to allocate the handler
  in the right area.  The xxxx_create_handler() function is also
  responsible for any initialization of the object before returning.

  For example, one should change:

  static handler *myisam_create_handler(TABLE_SHARE *table)
  {
    return new ha_myisam(table);
  }

  ->

  static handler *myisam_create_handler(TABLE_SHARE *table, MEM_ROOT *mem_root)
  {
    return new (mem_root) ha_myisam(table);
  }

- New optional virtual function: use_hidden_primary_key().
  This is called in case of an update/delete when
  (table_flags() and HA_PRIMARY_KEY_REQUIRED_FOR_DELETE) is defined
  but we don't have a primary key. This allows the handler to take precisions
  in remembering any hidden primary key to able to update/delete any
  found row. The default handler marks all columns to be read.

- handler::table_flags() now returns a ulonglong (to allow for more flags).

- New/changed table_flags()
  - HA_HAS_RECORDS	    Set if ::records() is supported
  - HA_NO_TRANSACTIONS	    Set if engine doesn't support transactions
  - HA_PRIMARY_KEY_REQUIRED_FOR_DELETE
                            Set if we should mark all primary key columns for
			    read when reading rows as part of a DELETE
			    statement. If there is no primary key,
			    all columns are marked for read.
  - HA_PARTIAL_COLUMN_READ  Set if engine will not read all columns in some
			    cases (based on table->read_set)
 - HA_PRIMARY_KEY_ALLOW_RANDOM_ACCESS
   			    Renamed to HA_PRIMARY_KEY_REQUIRED_FOR_POSITION.
 - HA_DUPP_POS              Renamed to HA_DUPLICATE_POS
 - HA_REQUIRES_KEY_COLUMNS_FOR_DELETE
			    Set this if we should mark ALL key columns for
			    read when when reading rows as part of a DELETE
			    statement. In case of an update we will mark
			    all keys for read for which key part changed
			    value.
  - HA_STATS_RECORDS_IS_EXACT
			     Set this if stats.records is exact.
			     (This saves us some extra records() calls
			     when optimizing COUNT(*))
			    

- Removed table_flags()
  - HA_NOT_EXACT_COUNT     Now one should instead use HA_HAS_RECORDS if
			   handler::records() gives an exact count() and
			   HA_STATS_RECORDS_IS_EXACT if stats.records is exact.
  - HA_READ_RND_SAME	   Removed (no one supported this one)

- Removed not needed functions ha_retrieve_all_cols() and ha_retrieve_all_pk()

- Renamed handler::dupp_pos to handler::dup_pos

- Removed not used variable handler::sortkey


Upper level handler changes:

- ha_reset() now does some overall checks and calls ::reset()
- ha_table_flags() added. This is a cached version of table_flags(). The
  cache is updated on engine creation time and updated on open.


MySQL level changes (not obvious from the above):

- DBUG_ASSERT() added to check that column usage matches what is set
  in the column usage bit maps. (This found a LOT of bugs in current
  column marking code).

- In 5.1 before, all used columns was marked in read_set and only updated
  columns was marked in write_set. Now we only mark columns for which we
  need a value in read_set.

- Column bitmaps are created in open_binary_frm() and open_table_from_share().
  (Before this was in table.cc)

- handler::table_flags() calls are replaced with handler::ha_table_flags()

- For calling field->val() you must have the corresponding bit set in
  table->read_set. For calling field->store() you must have the
  corresponding bit set in table->write_set. (There are asserts in
  all store()/val() functions to catch wrong usage)

- thd->set_query_id is renamed to thd->mark_used_columns and instead
  of setting this to an integer value, this has now the values:
  MARK_COLUMNS_NONE, MARK_COLUMNS_READ, MARK_COLUMNS_WRITE
  Changed also all variables named 'set_query_id' to mark_used_columns.

- In filesort() we now inform the handler of exactly which columns are needed
  doing the sort and choosing the rows.

- The TABLE_SHARE object has a 'all_set' column bitmap one can use
  when one needs a column bitmap with all columns set.
  (This is used for table->use_all_columns() and other places)

- The TABLE object has 3 column bitmaps:
  - def_read_set     Default bitmap for columns to be read
  - def_write_set    Default bitmap for columns to be written
  - tmp_set          Can be used as a temporary bitmap when needed.
  The table object has also two pointer to bitmaps read_set and write_set
  that the handler should use to find out which columns are used in which way.

- count() optimization now calls handler::records() instead of using
  handler->stats.records (if (table_flags() & HA_HAS_RECORDS) is true).

- Added extra argument to Item::walk() to indicate if we should also
  traverse sub queries.

- Added TABLE parameter to cp_buffer_from_ref()

- Don't close tables created with CREATE ... SELECT but keep them in
  the table cache. (Faster usage of newly created tables).


New interfaces:

- table->clear_column_bitmaps() to initialize the bitmaps for tables
  at start of new statements.

- table->column_bitmaps_set() to set up new column bitmaps and signal
  the handler about this.

- table->column_bitmaps_set_no_signal() for some few cases where we need
  to setup new column bitmaps but don't signal the handler (as the handler
  has already been signaled about these before). Used for the momement
  only in opt_range.cc when doing ROR scans.

- table->use_all_columns() to install a bitmap where all columns are marked
  as use in the read and the write set.

- table->default_column_bitmaps() to install the normal read and write
  column bitmaps, but not signaling the handler about this.
  This is mainly used when creating TABLE instances.

- table->mark_columns_needed_for_delete(),
  table->mark_columns_needed_for_delete() and
  table->mark_columns_needed_for_insert() to allow us to put additional
  columns in column usage maps if handler so requires.
  (The handler indicates what it neads in handler->table_flags())

- table->prepare_for_position() to allow us to tell handler that it
  needs to read primary key parts to be able to store them in
  future table->position() calls.
  (This replaces the table->file->ha_retrieve_all_pk function)

- table->mark_auto_increment_column() to tell handler are going to update
  columns part of any auto_increment key.

- table->mark_columns_used_by_index() to mark all columns that is part of
  an index.  It will also send extra(HA_EXTRA_KEYREAD) to handler to allow
  it to quickly know that it only needs to read colums that are part
  of the key.  (The handler can also use the column map for detecting this,
  but simpler/faster handler can just monitor the extra() call).

- table->mark_columns_used_by_index_no_reset() to in addition to other columns,
  also mark all columns that is used by the given key.

- table->restore_column_maps_after_mark_index() to restore to default
  column maps after a call to table->mark_columns_used_by_index().

- New item function register_field_in_read_map(), for marking used columns
  in table->read_map. Used by filesort() to mark all used columns

- Maintain in TABLE->merge_keys set of all keys that are used in query.
  (Simplices some optimization loops)

- Maintain Field->part_of_key_not_clustered which is like Field->part_of_key
  but the field in the clustered key is not assumed to be part of all index.
  (used in opt_range.cc for faster loops)

-  dbug_tmp_use_all_columns(), dbug_tmp_restore_column_map()
   tmp_use_all_columns() and tmp_restore_column_map() functions to temporally
   mark all columns as usable.  The 'dbug_' version is primarily intended
   inside a handler when it wants to just call Field:store() & Field::val()
   functions, but don't need the column maps set for any other usage.
   (ie:: bitmap_is_set() is never called)

- We can't use compare_records() to skip updates for handlers that returns
  a partial column set and the read_set doesn't cover all columns in the
  write set. The reason for this is that if we have a column marked only for
  write we can't in the MySQL level know if the value changed or not.
  The reason this worked before was that MySQL marked all to be written
  columns as also to be read. The new 'optimal' bitmaps exposed this 'hidden
  bug'.

- open_table_from_share() does not anymore setup temporary MEM_ROOT
  object as a thread specific variable for the handler. Instead we
  send the to-be-used MEMROOT to get_new_handler().
  (Simpler, faster code)



Bugs fixed:

- Column marking was not done correctly in a lot of cases.
  (ALTER TABLE, when using triggers, auto_increment fields etc)
  (Could potentially result in wrong values inserted in table handlers
  relying on that the old column maps or field->set_query_id was correct)
  Especially when it comes to triggers, there may be cases where the
  old code would cause lost/wrong values for NDB and/or InnoDB tables.

- Split thd->options flag OPTION_STATUS_NO_TRANS_UPDATE to two flags:
  OPTION_STATUS_NO_TRANS_UPDATE and OPTION_KEEP_LOG.
  This allowed me to remove some wrong warnings about:
  "Some non-transactional changed tables couldn't be rolled back"

- Fixed handling of INSERT .. SELECT and CREATE ... SELECT that wrongly reset
  (thd->options & OPTION_STATUS_NO_TRANS_UPDATE) which caused us to loose
  some warnings about
  "Some non-transactional changed tables couldn't be rolled back")

- Fixed use of uninitialized memory in ha_ndbcluster.cc::delete_table()
  which could cause delete_table to report random failures.

- Fixed core dumps for some tests when running with --debug

- Added missing FN_LIBCHAR in mysql_rm_tmp_tables()
  (This has probably caused us to not properly remove temporary files after
  crash)

- slow_logs was not properly initialized, which could maybe cause
  extra/lost entries in slow log.

- If we get an duplicate row on insert, change column map to read and
  write all columns while retrying the operation. This is required by
  the definition of REPLACE and also ensures that fields that are only
  part of UPDATE are properly handled.  This fixed a bug in NDB and
  REPLACE where REPLACE wrongly copied some column values from the replaced
  row.

- For table handler that doesn't support NULL in keys, we would give an error
  when creating a primary key with NULL fields, even after the fields has been
  automaticly converted to NOT NULL.

- Creating a primary key on a SPATIAL key, would fail if field was not
  declared as NOT NULL.


Cleanups:

- Removed not used condition argument to setup_tables

- Removed not needed item function reset_query_id_processor().

- Field->add_index is removed. Now this is instead maintained in
  (field->flags & FIELD_IN_ADD_INDEX)

- Field->fieldnr is removed (use field->field_index instead)

- New argument to filesort() to indicate that it should return a set of
  row pointers (not used columns). This allowed me to remove some references
  to sql_command in filesort and should also enable us to return column
  results in some cases where we couldn't before.

- Changed column bitmap handling in opt_range.cc to be aligned with TABLE
  bitmap, which allowed me to use bitmap functions instead of looping over
  all fields to create some needed bitmaps. (Faster and smaller code)

- Broke up found too long lines

- Moved some variable declaration at start of function for better code
  readability.

- Removed some not used arguments from functions.
  (setup_fields(), mysql_prepare_insert_check_table())

- setup_fields() now takes an enum instead of an int for marking columns
   usage.

- For internal temporary tables, use handler::write_row(),
  handler::delete_row() and handler::update_row() instead of
  handler::ha_xxxx() for faster execution.

- Changed some constants to enum's and define's.

- Using separate column read and write sets allows for easier checking
  of timestamp field was set by statement.

- Remove calls to free_io_cache() as this is now done automaticly in ha_reset()

- Don't build table->normalized_path as this is now identical to table->path
  (after bar's fixes to convert filenames)

- Fixed some missed DBUG_PRINT(.."%lx") to use "0x%lx" to make it easier to
  do comparision with the 'convert-dbug-for-diff' tool.


Things left to do in 5.1:

- We wrongly log failed CREATE TABLE ... SELECT in some cases when using
  row based logging (as shown by testcase binlog_row_mix_innodb_myisam.result)
  Mats has promised to look into this.

- Test that my fix for CREATE TABLE ... SELECT is indeed correct.
  (I added several test cases for this, but in this case it's better that
  someone else also tests this throughly).
  Lars has promosed to do this.
2006-06-04 18:52:22 +03:00
igor@rurik.mysql.com
692da27388 Post merge fix 2006-04-20 00:42:12 -07:00
igor@rurik.mysql.com
27cc6f4bc3 Merge rurik.mysql.com:/home/igor/dev/mysql-4.1-2
into  rurik.mysql.com:/home/igor/dev/mysql-5.0-0
2006-04-19 18:08:15 -07:00
evgen@moonbone.local
ac54aa2aee Fixed bug#14169: type of group_concat() result changed to blob if tmp_table was
used

In a simple queries a result of the GROUP_CONCAT() function was always of 
varchar type.
But if length of GROUP_CONCAT() result is greater than 512 chars and temporary
table is used during select then the result is converted to blob, due to
policy to not to store fields longer than 512 chars in tmp table as varchar
fields.

In order to provide consistent behaviour, result of GROUP_CONCAT() now
will always be converted to blob if it is longer than 512 chars.
Item_func_group_concat::field_type() is modified accordingly.
2006-04-12 23:05:38 +04:00
evgen@sunlight.local
7e4535e285 item_sum.cc, sql_select.cc:
After merge fix for bug#15560
item_sum.h:
   After merge fix for bug#15560
2006-03-30 19:04:21 +04:00