If check_quick_select returns non-empty range then the function cost_group_min_max
cannot return 0 as an estimate of the number of retrieved records.
Yet the function erroneously returned 0 as the estimate in some situations.
Final patch
-----------
This WL is about using this bitmap in all parts of the partition handler.
Thus for:
rnd_init/rnd_next
index_init/index_next and all other variants of index scans
read_range_... the various range scans implemented in the partition handler.
Also use those bitmaps in the various other calls that currently loop over all
partitions.
- Fixed tests
- Optimized new code
- Fixed some unlikely core dumps
- Better bug fixes for:
- #14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
- #14850 (ERROR 1062 when a quering a view using a Group By on a column that can be null
- post-...-post review fixes
- Added "integer range walking" that allows to do partition pruning for "a <=? t.field <=? b"
by finding used partitions for a, a+1, a+2, ..., b-1, b.
- Added more comments.
- Added a RANGE_OPT_PARAM::remove_jump_scans flag that disables construction of index_merge
SEL_TREEs that represent unusable conditions like "key1part1<c1 OR key2part2<c2"
- make prune_partitions() function handle the case where range analysis produces a list of
index_merge trees (it turned out that this is possible, appropriate test case added).
- Other small fixes.
Allow for configuration of the maximum number of indexes per table.
Added and used a configure.in macro.
Replaced fixed limits by the configurable limit.
Limited MyISAM indexes to its hard limit.
Fixed a bug in opt_range.cc for many indexes with InnoDB.
Tested for 2, 63, 64, 65, 127, 128, 129, 255, 256, and 257 indexes.
Testing this part of the bugfix requires rebuilding of the server
with different options. This cannot be done with our test suite.
Therefore I added the necessary test files to the bug report.
If you repeat the tests, please note that the ps_* tests fail for
everything but 64 indexes. This is because of differences in the
meta data, namely field lengths for index names etc.
by starting with an empty index set and adding indexes to it until it
becomes covering. If the set becomes covering after adding the first index,
return NULL and don't try constructing ROR-intersection of one index (which
caused a crash)
Loose index scan using only second part of multipart index was choosen, which
results in creating wrong keys and endless loop.
get_best_group_min_max() now allows loose index scan for distinct only if used
keyparts forms a prefix of the index.
The table opening process now works the following way:
- Create common TABLE_SHARE object
- Read the .frm file and unpack it into the TABLE_SHARE object
- Create a TABLE object based on the information in the TABLE_SHARE
object and open a handler to the table object
Other noteworthy changes:
- In TABLE_SHARE the most common strings are now LEX_STRING's
- Better error message when table is not found
- Variable table_cache is now renamed 'table_open_cache'
- New variable 'table_definition_cache' that is the number of table defintions that will be cached
- strxnmov() calls are now fixed to avoid overflows
- strxnmov() will now always add one end \0 to result
- engine objects are now created with a TABLE_SHARE object instead of a TABLE object.
- After creating a field object one must call field->init(table) before using it
- For a busy system this change will give you:
- Less memory usage for table object
- Faster opening of tables (if it's has been in use or is in table definition cache)
- Allow you to cache many table definitions objects
- Faster drop of table
Bad examples of usage of a string with its length fixed.
The incorrect length in the trigger file configuration descriptor
fixed (BUG#14090).
A hook for unknown keys added to the parser to support old .TRG files.
large table gives server crash": make sure that when a MyISAM temporary
table is created for a cursor, it's created in its memory root,
not the memory root of the current query.
Invalid date like 2000-02-32 wasn't converted to int, which lead to not
using index and comparison with field as astring, which results in slow
query execution.
convert_constatn_item() and get_mm_leaf() now forces MODE_INVALID_DATES to
allow such conversion.
Ensure that ccache is also used for C programs
mysql: Ensure that 'delimiter' works the same way in batch mode as in normal mode
mysqldump: Change to use ;; (instead of //) as a stored procedure/trigger delimiter
Fixed test cases by adding missing DROP's and rename views to be of type 'v#'
Removed MY_UNIX_PATH from fn_format()
Removed current_db_used from TABLE_LIST
Removed usage of 'current_thd' in Item_splocal
Removed some compiler warnings
A bit faster longlong2str code
