missing after downgrade
Obsolete arc/ directory and view .frm file backup support
has been removed by the patch for bug 17823. However, that
bugfix caused a problem with "live downgrades" of the
server: if we rename some view 4 times under 5.1.29/5.0.72
and then try to rename it under 5.1.28/5.0.70 on the same
database, the server fails with a error:
query 'RENAME TABLE ... TO ...' failed: 6: Error on
delete of '....frm-0001' (Errcode: 2)
Also .frm file of that view may be lost (renamed to .frm~).
The server failed because it tried to rename latest 3
backup .frm files renaming the view: the server used an
integer value of the "revision" field of .frm file to
extract those file names. After the fix for bug 17823 those
files were not created/maintained any more, however the
"revision" field was incremented as usual. So, the server
failed renaming non existent files.
This fix solves the problem by removing the support for
"revision" .frm file field:
1. New server silently ignores existent "revision" fields
in old .frm files and never write it down;
2. Old server assumes, that missing "revision" field in new
.frm files means default value of 0.
3. Accordingly to the fix for bug 17823 the new server
drops arc/ directory on alter/rename view, so after
"live downgrade" old server begins maintenance of the
arc/ directory from scratch without conflicts with .frm
files.
Server created "arc" directories inside database directories and
maintained there useless copies of .frm files.
Creation and renaming procedures of those copies as well as
creation of "arc" directories has been discontinued.
Removal procedure has been kept untouched to be able to
cleanup existent database directories by the DROP DATABASE
query. Also view renaming procedure has been updated to remove
these directories.
warnings in sql_trigger.cc and sql_view.cc".
According to the current version of C++ standard offsetof() macro
can't be used for non-POD types. So warnings were emitted when we
tried to use this macro for TABLE_LIST and Table_triggers_list
classes. Note that despite of these warnings it was probably safe
thing to do.
This fix tries to circumvent this limitation by implementing
custom version of offsetof() macro to be used with these
classes. This hack should go away once we will refactor
File_parser class.
Alternative approaches such as disabling this warning for
sql_trigger.cc/sql_view.cc or for the whole server were
considered less explicit. Also I was unable to find a way
to disable particular warning for particular _part_ of
file in GCC.
in older version.
The problem is that TRN-files created in "old" versions contain
junk in trigger_table field, which is not acceptable in "new" versions.
- Added empty constructors and virtual destructors to many classes and structs
- Removed some usage of the offsetof() macro to instead use C++ class pointers
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.
Mostly needed for Monty for him getting notion what needed for triggers
from new .FRM format.
Things to be done:
- Right placement of trigger's invocations
- Right handling of errors in triggers (including transaction rollback)
- Support for priviliges
- Right handling of DROP/RENAME table (hope that it will be handled automatically
with merging of .TRG into .FRM file)
- Saving/restoring some information critical for trigger creation and replication
with their definitions (e.g. sql_mode, creator, ...)
- Replication
Already has some known bugs so probably not for general review.
