numbers)
Before this patch, the code in the class Log_to_csv_event_handler, which is
used by the global LOGGER object to write to the tables mysql.slow_log and
mysql_general_log, was supporting only records of the format defined for
these tables in the database creation scripts.
Also before this patch, the server would allow, with certain limitations,
to perform ALTER TABLE on the LOG TABLES.
As implemented, the behavior of the server, with regards to LOG TABLES,
is inconsistent:
- either ALTER TABLES on LOG TABLES should be prohibited,
and the code writing to these tables can make assumptions on the record
format,
- or ALTER TABLE on LOG TABLES is permitted, in which case the code
writing a record to these tables should be more flexible and honor
new fields.
In particular, adding an AUTO_INCREMENT column to the logs,
does not work as expected (per the bug report).
Given that the ALTER TABLE on log tables statement has been explicitly
implemented to check that the log should be off to perform the operation,
and that current test cases already cover this, the user expectation is
already set that this is a "feature" and should be supported.
With this patch, the server will:
- populate AUTO INCREMENT columns if present,
- populate any additional column with it's default value
when writing a record to the LOG TABLES.
Tests are provided, that detail the precise sequence of statements
a SUPER user might want to perform to add more columns to the log tables.
Bug 28127 (Some valid identifiers names are not parsed correctly)
Bug 26302 (MySQL server cuts off trailing "*/" from comments in SP/func)
This patch is the second part of a major cleanup, required to fix
Bug 25411 (trigger code truncated).
The root cause of the issue stems from the function skip_rear_comments,
which was a work around to remove "extra" "*/" characters from the query
text, when parsing a query and reusing the text fragments to represent a
view, trigger, function or stored procedure.
The reason for this work around is that "special comments",
like /*!50002 XXX */, were not parsed properly, so that a query like:
AAA /*!50002 BBB */ CCC
would be seen by the parser as "AAA BBB */ CCC" when the current version
is greater or equal to 5.0.2
The root cause of this stems from how special comments are parsed.
Special comments are really out-of-bound text that appear inside a query,
that affects how the parser behave.
In nature, /*!50002 XXX */ in MySQL is similar to the C concept
of preprocessing :
#if VERSION >= 50002
XXX
#endif
Depending on the current VERSION of the server, either the special comment
should be expanded or it should be ignored, but in all cases the "text" of
the query should be re-written to strip the "/*!50002" and "*/" markers,
which does not belong to the SQL language itself.
Prior to this fix, these markers would leak into :
- the storage format for VIEW,
- the storage format for FUNCTION,
- the storage format for FUNCTION parameters, in mysql.proc (param_list),
- the storage format for PROCEDURE,
- the storage format for PROCEDURE parameters, in mysql.proc (param_list),
- the storage format for TRIGGER,
- the binary log used for replication.
In all cases, not only this cause format corruption, but also provide a vector
for dormant security issues, by allowing to tunnel code that will be activated
after an upgrade.
The proper solution is to deal with special comments strictly during parsing,
when accepting a query from the outside world.
Once a query is parsed and an object is created with a persistant
representation, this object should not arbitrarily mutate after an upgrade.
In short, special comments are a useful but limited feature for MYSQLdump,
when used at an *interface* level to facilitate import/export,
but bloating the server *internal* storage format is *not* the proper way
to deal with configuration management of the user logic.
With this fix:
- the Lex_input_stream class now acts as a comment pre-processor,
and either expands or ignore special comments on the fly.
- MYSQLlex and sql_yacc.yy have been cleaned up to strictly use the
public interface of Lex_input_stream. In particular, how the input stream
accepts or rejects a character is private to Lex_input_stream, and the
internal buffer pointers of that class are strictly private, and should not
be tempered with during parsing.
This caused many changes mostly in sql_lex.cc.
During the code cleanup in case MY_LEX_NUMBER_IDENT,
Bug 28127 (Some valid identifiers names are not parsed correctly)
was found and fixed.
By parsing special comments properly, and removing the function
'skip_rear_comments' [sic],
Bug 26302 (MySQL server cuts off trailing "*/" from comments in SP/func)
has been fixed as well.
Coding style: classes start with a capital letter.
Rename some classes related to parsing:
create_field -> Create_field
foreign_key -> Foreign_key
key_part_spec -> Key_part_spec
- add odirect option for lcp+backup+redo log to lower CPU/kswapd usage
- writing odirect removes need for kernel write buffers avoiding kswapd to kick in
