There are (at least) two implementations of the checksum
computation. One is in MyISAM for the quick checksum. It
is executed on every row change. The other is in the
SQL layer for the extended checksum. It retrieves all rows
of a table via the respective storage engine.
In former MySQL versions varchars were stored with their
maximum length, but now with their real length similar to
blobs.
This change had been forgotten to take care of in the
extended checksum calculation. Hence too much data was
checksumed. In MyISAM this change had been taken care of
already. Only the real data is included in the checksum.
I changed mysql_checksum_table() so that it uses the
length information of true varchar fields instead
of the field length like in former varchar
implementations.
Optimised version of ADD/DROP/REORGANIZE partitions for
non-NDB storage engines.
New syntax to handle REBUILD/OPTIMIZE/ANALYZE/CHECK/REPAIR partitions
Quite a few bug fixes
NDB cluster is not fully supported. This will be added with
WL 1892 (NDB Handler: Add support for CREATE/DROP INDEX).
Some preparatory code for this is already present though.
A change for the "duplicate key" error message is planned
for another changeset.
which makes it possible to run RENAME TABLE
on old tables when upgrading from 5.0.
TODO: A stored procedure to rename all tables and
databases with old name format into new format,
it will simplify upgrade.
sql_table.cc:
Making old tables seen with "#mysql50#" prefix.
Adding warning into .err log when an old name is found.
sql_show.cc:
Skip non-directories before filename_to_tablename
call, to avoid unnecessary warnings.
strfunc.cc:
Adding "error" argument to strconvert()
mysql_priv.h:
Adding "error" agrument to strconvert()
- Encoding itself, implemented as a charset
"filename". Originally planned to use '.'
as an escape character, but now changed to '@'
for two reasons: "ls" does not return
file names starting with '.' considering them
as a kind of hidden files; some platforms
do not allow several dots in a file name.
- replacing many calls of my_snprintf() and
strnxmov() to the new build_table_filename().
- Adding MY_APPEND_EXT mysys flag, to append
an extention rather that replace it.
- Replacing all numeric constants in fn_format
flag arguments to their mysys definitions, e.g.
MY_UNPACK_FILENAME,
- Predictability in several function/methods:
when a table name can appear with or withot .frm
extension. Some functions/methods were changed
so accept names strictly with .frm, other - strictly
without .frm extensions. Several DBUG_ASSERTs were
added to check whether an extension is passed.
Many files:
table name to file name encoding
mysql_priv.h:
Prototypes for new table name encoding tools.
ctype-utf8.c:
Implementing "filename" charset for
table name to file name encoding.
row0mysql.c:
Fixing table name prefix.
mf_format.c:
Adding MY_APPEND_EXT processing.
Many files:
Fixing tests.
my_sys.h:
Adding new flag to append rather than replace an extension.
m_ctype.h:
Adding "filename" charset definition.
CREATE TABLE and PS/SP": make sure that 'typelib' object for
ENUM values and 'Item_string' object for DEFAULT clause are
created in the statement memory root.
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
