On parsing statements for which a starting backtick (`) delimiter doesn't have
a corresponding ending backtick, a current pointer to a position inside a
pre-processed buffer could go beyond the end of the buffer.
This bug report caused by the commit d496765903
"MDEV-22022 Various mangled SQL statements will crash 10.3 to 10.5 debug builds".
In order to fix the issue both pointers m_ptr and m_cpp_ptr must be
rolled back to previous position in raw input and pre-processed input streams
correspondingly in case end of query reached during parsing.
Due to a premature cleanup of the unit that specified a recursive CTE
used in the second operand of union the server fell into an infinite
loop in the reported test case. In other cases this premature cleanup
could cause other problems.
The bug is the result of a not quite correct fix for MDEV-17024. The
unit that specifies a recursive CTE has to be cleaned only after the
cleanup of the last external reference to this CTE. It means that
cleanups of the unit triggered not by the cleanup of a external
reference to the CTE must be blocked.
Usage of local table chains in selects to get external references to
recursive CTEs was not correct either because of possible merges of
some selects.
Also fixed a minor bug in st_select_lex::set_explain_type() that caused
typing 'RECURSIVE UNION' instead of 'UNION' in EXPLAIN output for external
references to a recursive CTE.
Reimplement MDEV-14275 Improving memory utilization for information schema
Postpone temp table instantiation until after setup_fields().
Replace all unused (not marked in read_set) columns in an I_S table
with CHAR(0). This can drastically reduce the footprint of a MEMORY
table (a TABLE_CATALOG alone is 1538 bytes per row).
This does not change the engine. If the table was decided to be Aria
(because of, say, blobs) then after optimization it'll stay Aria
even if all blobs were removed.
Note 1: when transforming table structure, share->blob_fields is
preserved, otherwise Aria might switch from DYNAMIC to STATIC row format
and expect a special field for a deleted mark, which create_tmp_tabe
didn't provide.
Note 2: optimizer was doing handler::info() (to know the number of rows)
before the temp table is populated. That didn't make much sense. Now
it's done before the table is even instantiated. Preserve the old
behavior and report 0 rows.
This reverts e2664ee836 and a8458a2345
Lex_input_stream::scan_ident_delimited() could go beyond the end
of the input when a starting backtick (`) delimiter did not have a
corresponding ending backtick.
Fix: catch the case when yyGet() returns 0, which means
either eof-of-query or straight 0x00 byte inside backticks,
and make the parser fail on syntax error, displaying the left
backtick as the syntax error place.
In case of filename in a script like this:
SET CHARACTER_SET_CLIENT=17; -- 17 is 'filename'
SELECT doc.`Children`.0 FROM t1;
the ending backtick was not recognized as such because my_charlen() returns 0 for
a straight backtick (backticks must normally be encoded as @0060 in filename).
The same fix works for 'filename': the execution skips the backtick
and reaches the end of the query, then yyGet() returns 0.
This fix is OK for now. But eventually 'filename' should either be disallowed
as a parser character set, or fixed to handle encoded punctuation properly.
- Adding optional qualifiers to data types:
CREATE TABLE t1 (a schema.DATE);
Qualifiers now work only for three pre-defined schemas:
mariadb_schema
oracle_schema
maxdb_schema
These schemas are virtual (hard-coded) for now, but may turn into real
databases on disk in the future.
- mariadb_schema.TYPE now always resolves to a true MariaDB data
type TYPE without sql_mode specific translations.
- oracle_schema.DATE translates to MariaDB DATETIME.
- maxdb_schema.TIMESTAMP translates to MariaDB DATETIME.
- Fixing SHOW CREATE TABLE to use a qualifier for a data type TYPE
if the current sql_mode translates TYPE to something else.
The above changes fix the reported problem, so this script:
SET sql_mode=ORACLE;
CREATE TABLE t2 AS SELECT mariadb_date_column FROM t1;
is now replicated as:
SET sql_mode=ORACLE;
CREATE TABLE t2 (mariadb_date_column mariadb_schema.DATE);
and the slave can unambiguously treat DATE as the true MariaDB DATE
without ORACLE specific translation to DATETIME.
Similar,
SET sql_mode=MAXDB;
CREATE TABLE t2 AS SELECT mariadb_timestamp_column FROM t1;
is now replicated as:
SET sql_mode=MAXDB;
CREATE TABLE t2 (mariadb_timestamp_column mariadb_schema.TIMESTAMP);
so the slave treats TIMESTAMP as the true MariaDB TIMESTAMP
without MAXDB specific translation to DATETIME.
* Fix the crash: IN-to-EXISTS rewrite causes an error (and so
JOIN::optimize() fails with an error, too), don't call
update_used_tables(). Terminate the query execution instead.
* Fix the cause of the error in the IN-to-EXISTS rewrite: don't do
the rewrite if doing it will cause an error of this kind:
This version of MariaDB doesn't yet support 'SUBQUERY in ROW in left
expression of IN/ALL/ANY'
* Fix another issue exposed by this testcase:
JOIN::setup_subquery_caches() may be invoked before any select has
saved its query plan, and will crash because none of the SELECTs
has called create_explain_query_if_not_exists() to create the Explain
Data Structure for this SELECT.
TODO: When merging this to 10.2, remove the poorly-placed call to
create_explain_query_if_not_exists made by fix for M_D_E_V-16153
Allocate space for fields inside the window function (arguments, PARTITION BY and ORDER BY clause)
in the ref pointer array. All fields inside the window function are part of the temporary
table that is required for the window function computation.
The opt_for_user subrule was incorrectly scanned before sp_create_assignment_lex(),
so the user name and the host were created on a wrong memory root.
- Reoganizing the grammar to make sure that sp_create_assignment_lex()
is called immediately after PASSWORD_SYM is scanned, so all attributes
are then allocated on its memory root.
- Moving the semantic code as methods to LEX, so the grammar looks as simple as possible.
- Changing text_or_password to be of the data type USER_AUTH*.
As a side effect, the LEX::definer member is now not used when processing
the SET PASSWORD statement. Everything is done using Bison's stack.
The bug sas introduced by this commit:
commit bf5a144e16
Cause:
In case of version based condtional comments, if the condition evaluates
to false, it is converted to a regular comment for replication by
replacing "!" by " ".
Nested comment in a conditional comment is replicated as is. Nested
comments are supported only in case of conditional comments and when a
the comment on slave is no more a conditional comment, the statement
execution fails on the slave.
Fix:
Convert the nested comment, start from "/*" to "(*" and comment end from
"*/" to "*)" for replication.
Change-Id: I1a8e385a267b2370529eade094f0258fa96886c0
In main.index_merge_myisam we remove the test that was added in
commit a2d24def8c because
it duplicates the test case that was added in
commit 5af12e4635.
