otherwise we'd need to store sql_mode *per vcol*
(consider CREATE INDEX...) and how SHOW CREATE TABLE would
support that?
Additionally, get rid of vcol::expr_str, just to make sure
the string is always generated and never leaked in the
original form.
* 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
* don't issue an error for ER_KEY_BASED_ON_GENERATED_VIRTUAL_COLUMN
* support keyread on vcols
* callback into the server to compute vcol values from mi_check/mi_repair
* DMLs just work. Automatically.
