The algorithm change is based on a MySQL 8.0 fix for
BUG #26818787: ASSERTION: DATA0DATA.IC:430:TUPLE
by Krzysztof Kapuścik
ee606e62bb
If a record had been inserted in place of a delete-marked purgeable
record by modifying that record, and purge was accessing that record
before the off-page columns were written, row_build_index_entry()
would have returned NULL, causing a crash.
row_vers_non_virtual_fields_equal(): Check whether all non-virtual fields
of an index are equal. Replaces row_vers_non_vc_match(). A more complex
version of this function was called row_vers_non_vc_index_entry_match()
in the MySQL 8.0 fix.
row_vers_impl_x_locked_low(): This change is not directly related to
the reported problem, but apparently to the removal of the function
row_vers_non_vc_match(). This function checks if a secondary index
record was modified by a transaction that has not been committed yet.
For comparing the non-virtual columns, construct a secondary index
tuple from the table row.
row_vers_vc_matches_cluster(): Replace row_vers_non_vc_match() with
code that is equivalent to the row_vers_non_vc_index_entry_match()
in the MySQL 8.0 fix. Also, deduplicate some code by using goto.
The InnoDB background tasks can modify tables while LOCK TABLES...WRITE
is in effect. The purge of InnoDB history always worked like this in
MariaDB, but in MySQL 5.7 it sometimes yields to LOCK TABLES.
Also, make gcol.innodb_virtual_index run the purge for an UPDATE
before DROP TABLE is executed.
* remove old 5.2+ InnoDB support for virtual columns
* enable corresponding parts of the innodb-5.7 sources
* copy corresponding test cases from 5.7
* copy detailed Alter_inplace_info::HA_ALTER_FLAGS flags from 5.7
- and more detailed detection of changes in fill_alter_inplace_info()
* more "innodb compatibility hooks" in sql_class.cc to
- create/destroy/reset a THD (used by background purge threads)
- find a prelocked table by name
- open a table (from a background purge thread)
* different from 5.7:
- new service thread "thd_destructor_proxy" to make sure all THDs are
destroyed at the correct point in time during the server shutdown
- proper opening/closing of tables for vcol evaluations in
+ FK checks (use already opened prelocked tables)
+ purge threads (open the table, MDLock it, add it to tdc, close
when not needed)
- cache open tables in vc_templ
- avoid unnecessary allocations, reuse table->record[0] and table->s->default_values
- not needed in 5.7, because it overcalculates:
+ tell the server to calculate vcols for an on-going inline ADD INDEX
+ calculate vcols for correct error messages
* update other engines (mroonga/tokudb) accordingly
