mysqldump --skip-events --all-databases dumped data of the mysqld.event table,
and during the restoration from this dump events were created in spite
of the --skip-events option.
The mysqldump client has been modified to ignore mysql.event table data
in case of --skip-events options.
DELETE FROM ... USING ... statements with the following type of
ambiguous aliasing gave unexpected results:
DELETE FROM t1 AS alias USING t1, t2 AS alias WHERE t1.a = alias.a;
This query would leave table t1 intact but delete rows from t2.
Fixed by changing DELETE FROM ... USING syntax so that only alias
references (as opposed to alias declarations) may be used in FROM.
When dumping database from a 4.x server, the mysqldump client
inserted a delimiter sign inside special commentaries of the form:
/*!... CREATE DATABASE IF NOT EXISTS ... ;*/
During restoration that dump file was splitten by delimiter signs on
the client side, and the rest of some commentary strings was prepended
to following statements.
The 4x_server_emul test case option has been added for use with the
DBUG_EXECUTE_IF debugging macro. This option affects debug server
builds only to emulate particular behavior of a 4.x server for
the mysqldump client testing. Non-debugging builds are not affected.
comments)
This change set is for 5.1 (manually merged)
Before this fix, the server would accept queries that contained comments,
even when the comments were not properly closed with a '*' '/' marker.
For example,
select 1 /* + 2 <EOF>
would be accepted as
select 1 /* + 2 */ <EOF>
and executed as
select 1
With this fix, the server now rejects queries with unclosed comments
as syntax errors.
Both regular comments ('/' '*') and special comments ('/' '*' '!') must be
closed with '*' '/' to be parsed correctly.
Problem:
In cases when a client-side macro appears inside a server-side comment, the add_line() function in mysql.cc discarded all characters until the next delimiter to remove macro arguments from the query string. This resulted in broken queries being sent to the server when the next delimiter character appeared past the comment's boundaries, because the comment closing sequence ('*/') was discarded.
Fix:
If a client-side macro appears inside a server-side comment, discard all characters in the comment after the macro (that is, until the end of the comment rather than the next delimiter).
This is a minimal fix to allow only simple cases used by the mysqlbinlog utility. Limitations that are worth documenting:
- Nested server-side and/or client-side comments are not supported by mysql.cc
- Using client-side macros in multi-line server-side comments is not supported
- All characters after a client-side macro in a server-side comment will be omitted from the query string (and thus, will not be sent to server).
comments)
Before this fix, the server would accept queries that contained comments,
even when the comments were not properly closed with a '*' '/' marker.
For example,
select 1 /* + 2 <EOF>
would be accepted as
select 1 /* + 2 */ <EOF>
and executed as
select 1
With this fix, the server now rejects queries with unclosed comments
as syntax errors.
Both regular comments ('/' '*') and special comments ('/' '*' '!') must be
closed with '*' '/' to be parsed correctly.
Bug#21422 GRANT/REVOKE possible inside stored function, probably in a trigger
Bug#17244 GRANT gives strange error message when used in a stored function
GRANT/REVOKE statements are non-transactional (no explicit transaction
boundaries) in nature and hence are forbidden inside stored functions and
triggers, but they weren't being effectively forbidden. Furthermore, the
absence of implict commits makes changes made by GRANT/REVOKE statements to
not be rolled back.
The implemented fix is to issue a implicit commit with every GRANT/REVOKE
statement, effectively prohibiting these statements in stored functions
and triggers. The implicit commit also fixes the replication bug, and looks
like being in concert with the behavior of DDL and administrative statements.
Since this is a incompatible change, the following sentence should be
added to the Manual in the very end of the 3rd paragraph, subclause
13.4.3 "Statements That Cause an Implicit Commit": "Beginning with
MySQL 5.0.??, the GRANT and REVOKE statements cause an implicit commit."
Patch contributed by Vladimir Shebordaev
and strategy (explain)
The fix for WL3527 adds tests that test if the index usage hints
combinations don't cause syntax errors.
The EXPLAIN for one of these tests can be affected by the size of the
rowid on the disk (affected by the presence of large file support).
Fixed to avoid the platform dependent test result by removing the
irrelevant columns from the EXPLAIN result.
This is a performance bug, affecting in particular the bison generated code
for the parser.
Prior to this fix, the grammar used a long chain of reduces to parse an
expression, like:
bit_expr -> bit_term
bit_term -> bit_factor
bit_factor -> value_expr
value_expr -> term
term -> factor
etc
This chain of reduces cause the internal state automaton in the generated
parser to execute more state transitions and more reduces, so that the
generated MySQLParse() function would spend a lot of time looping to execute
all the grammar reductions.
With this patch, the grammar has been reorganized so that rules are more
"flat", limiting the depth of reduces needed to parse <expr>.
Tests have been written to enforce that relative priorities and properties
of operators have not changed while changing the grammar.
See the bug report for performance data.
The optimization that uses a unique index to remove GROUP BY did not
ensure that the index was actually used, thus violating the ORDER BY
that is implied by GROUP BY.
Fixed by replacing GROUP BY with ORDER BY if the GROUP BY clause contains
a unique index over non-nullable field(s). In case GROUP BY ... ORDER BY
null is used, GROUP BY is simply removed.
Currently the Last_query_cost session status variable shows
only the cost of a single flat subselect. For complex queries
(with subselects or unions etc) Last_query_cost is not valid
as it was showing the cost for the last optimized subselect.
Fixed by reseting to zero Last_query_cost when the complete
cost of the query cannot be determined.
Last_query_cost will be non-zero only for single flat queries.
