The used code is largely based on code from Tencent
The problem is that in some rare cases there may be a conflict between .frm
files and the files in the storage engine. In this case the DROP TABLE
was not able to properly drop the table.
Some MariaDB/MySQL forks has solved this by adding a FORCE option to
DROP TABLE. After some discussion among MariaDB developers, we concluded
that users expects that DROP TABLE should always work, even if the
table would not be consistent. There should not be a need to use a
separate keyword to ensure that the table is really deleted.
The used solution is:
- If a .frm table doesn't exists, try dropping the table from all storage
engines.
- If the .frm table exists but the table does not exist in the engine
try dropping the table from all storage engines.
- Update storage engines using many table files (.CVS, MyISAM, Aria) to
succeed with the drop even if some of the files are missing.
- Add HTON_AUTOMATIC_DELETE_TABLE to handlerton's where delete_table()
is not needed and always succeed. This is used by ha_delete_table_force()
to know which handlers to ignore when trying to drop a table without
a .frm file.
The disadvantage of this solution is that a DROP TABLE on a non existing
table will be a bit slower as we have to ask all active storage engines
if they know anything about the table.
Other things:
- Added a new flag MY_IGNORE_ENOENT to my_delete() to not give an error
if the file doesn't exist. This simplifies some of the code.
- Don't clear thd->error in ha_delete_table() if there was an active
error. This is a bug fix.
- handler::delete_table() will not abort if first file doesn't exists.
This is bug fix to handle the case when a drop table was aborted in
the middle.
- Cleaned up mysql_rm_table_no_locks() to ensure that if_exists uses
same code path as when it's not used.
- Use non_existing_Table_error() to detect if table didn't exists.
Old code used different errors tests in different position.
- Table_triggers_list::drop_all_triggers() now drops trigger file if
it can't be parsed instead of leaving it hanging around (bug fix)
- InnoDB doesn't anymore print error about .frm file out of sync with
InnoDB directory if .frm file does not exists. This change was required
to be able to try to drop an InnoDB file when .frm doesn't exists.
- Fixed bug in mi_delete_table() where the .MYD file would not be dropped
if the .MYI file didn't exists.
- Fixed memory leak in Mroonga when deleting non existing table
- Fixed memory leak in Connect when deleting non existing table
Bugs fixed introduced by the original version of this commit:
MDEV-22826 Presence of Spider prevents tables from being force-deleted from
other engines
and enable using special column in them.
modified: storage/connect/tabzip.cpp
modified: storage/connect/tabzip.h
- Fix some compiler errors
modified: storage/connect/tabcmg.cpp
- multi_range_read_info_const now uses the new records_in_range interface
- Added handler::avg_io_cost()
- Don't calculate avg_io_cost() in get_sweep_read_cost if avg_io_cost is
not 1.0. In this case we trust the avg_io_cost() from the handler.
- Changed test_quick_select to use TIME_FOR_COMPARE instead of
TIME_FOR_COMPARE_IDX to align this with the rest of the code.
- Fixed bug when using test_if_cheaper_ordering where we didn't use
keyread if index was changed
- Fixed a bug where we didn't use index only read when using order-by-index
- Added keyread_time() to HEAP.
The default keyread_time() was optimized for blocks and not suitable for
HEAP. The effect was the HEAP prefered table scans over ranges for btree
indexes.
- Fixed get_sweep_read_cost() for HEAP tables
- Ensure that range and ref have same cost for simple ranges
Added a small cost (MULTI_RANGE_READ_SETUP_COST) to ranges to ensure
we favior ref for range for simple queries.
- Fixed that matching_candidates_in_table() uses same number of records
as the rest of the optimizer
- Added avg_io_cost() to JT_EQ_REF cost. This helps calculate the cost for
HEAP and temporary tables better. A few tests changed because of this.
- heap::read_time() and heap::keyread_time() adjusted to not add +1.
This was to ensure that handler::keyread_time() doesn't give
higher cost for heap tables than for normal tables. One effect of
this is that heap and derived tables stored in heap will prefer
key access as this is now regarded as cheap.
- Changed cost for index read in sql_select.cc to match
multi_range_read_info_const(). All index cost calculation is now
done trough one function.
- 'ref' will now use quick_cost for keys if it exists. This is done
so that for '=' ranges, 'ref' is prefered over 'range'.
- scan_time() now takes avg_io_costs() into account
- get_delayed_table_estimates() uses block_size and avg_io_cost()
- Removed default argument to test_if_order_by_key(); simplifies code
Prototype change:
- virtual ha_rows records_in_range(uint inx, key_range *min_key,
- key_range *max_key)
+ virtual ha_rows records_in_range(uint inx, const key_range *min_key,
+ const key_range *max_key,
+ page_range *res)
The handler can ignore the page_range parameter. In the case the handler
updates the parameter, the optimizer can deduce the following:
- If previous range's last key is on the same block as next range's first
key
- If the current key range is in one block
- We can also assume that the first and last block read are cached!
This can be used for a better calculation of IO seeks when we
estimate the cost of a range index scan.
The parameter is fully implemented for MyISAM, Aria and InnoDB.
A separate patch will update handler::multi_range_read_info_const() to
take the benefits of this change and also remove the double
records_in_range() calls that are not anymore needed.
- Only indentation changes in sql_rename.cc
- Ignore some WSREP error messages when there isn't a internet connection
- Force restart of stat_tables_part.test to make result stable
- Fixed compiler warnings in CONNECT
This was to remove a performance regression between 10.3 and 10.4
In 10.5 we will have a better implementation of records_in_range
that will enable us to get more statistics.
This change was not done in 10.4 because the 10.5 will be part of
a larger change that is not suitable for the GA 10.4 version
Other things:
- Changed default handler block_size to 8192 to fix things statistics
for engines that doesn't set the block size.
- Fixed a bug in spider when using multiple part const ranges
(Patch from Kentoku)
e.g.
- dont -> don't
- occurence -> occurrence
- succesfully -> successfully
- easyly -> easily
Also remove trailing space in selected files.
These changes span:
- server core
- Connect and Innobase storage engine code
- OQgraph, Sphinx and TokuDB storage engines
Related to MDEV-21769.
Import complex XML from multiple files in MariaDB
Some row results are missing and replaced by the last file one.
Thats because Nx and Sx column members are not reset when changing file.
modified: storage/connect/tabxml.cpp
modified: storage/connect/tabxml.h
Import complex XML from multiple files in MariaDB
Some row results are missing and replaced by the last file one.
Thats because Nx and Sx column members are not reset when changing file.
modified: storage/connect/tabxml.cpp
modified: storage/connect/tabxml.h
Import complex XML from multiple files in MariaDB
Some row results are missing and replaced by the last file one.
Thats because Nx and Sx column members are not reset when changing file.
modified: storage/connect/tabxml.cpp
modified: storage/connect/tabxml.h
This task deals with packing the non-sorted fields (or addon fields).
This would lead to efficient usage of the memory allocated for the sort buffer.
The changes brought by this feature are
1) Sort buffers would have records of variable length
2) Each record in the sort buffer would be stored like
<sort_key1><sort_key2>....<addon_length><null_bytes><field1><field2>....
addon_length is the extra bytes that are required to store the variable
length of addon field across different records.
3) Changes in rr_unpack_from_buffer and rr_from_tempfile to take into account
the variable length of records.
Ported WL#1509 Pack values of non-sorted fields in the sort buffer from
MySQL by Tor Didriksen
Failed compile when XML table type is not supported.
Was because XMLDEF was unconditionally called from REST table.
modified: storage/connect/tabrest.cpp
- Make cmake less verbose
modified: storage/connect/CMakeLists.txt
- Hide Switch_to_definer_security_ctx not defined for 10.1 and 10.0
modified: storage/connect/ha_connect.cc
Failed compile when XML table type is not supported.
Was because XMLDEF was unconditionally called from REST table.
modified: storage/connect/tabrest.cpp
