Bug#27047[partial]: INFORMATION_SCHEMA table cannot have BIGINT \
fields
No Information_schema table has ever needed floating-point data
before. Transforming all floating point to a string and back to a
number causes a real data problem on Windows, where the libc may
pad the exponent with more leading zeroes than we expect and the
significant digits are truncated away.
This also makes interpreting an unimplemented type as a string into
a fatal error in debug builds. Thus, we will catch problems when we
try to use those types in new I_S tables.
Different set of conditions is used to verify
the validity of index definitions over a GEOMETRY
column in ALTER TABLE and CREATE TABLE.
The difference was on how sub-keys notion validity
is checked.
Fixed by extending the CREATE TABLE condition to
support the cases allowed in ALTER TABLE.
Made the SHOW CREATE TABLE not to display spatial
indexes using the sub-key notion.
The crash happens because second filling of the same I_S table happens in
case of subselect with order by. table->sort.io_cache previously allocated
in create_sort_index() is deleted during second filling
(function get_schema_tables_result). There are two places where
I_S table can be filled: JOIN::exec and create_sort_index().
To fix the bug we should check if the table was already filled
in one of these places and skip processing of the table in second.
- Removed not used variables and functions
- Added #ifdef around code that is not used
- Renamed variables and functions to avoid conflicts
- Removed some not used arguments
Fixed some class/struct warnings in ndb
Added define IS_LONGDATA() to simplify code in libmysql.c
I did run gcov on the changes and added 'purecov' comments on almost all lines that was not just variable name changes
Bug#4968 "Stored procedure crash if cursor opened on altered table"
Bug#19733 "Repeated alter, or repeated create/drop, fails"
Bug#19182 "CREATE TABLE bar (m INT) SELECT n FROM foo; doesn't work from
stored procedure."
Bug#6895 "Prepared Statements: ALTER TABLE DROP COLUMN does nothing"
Bug#22060 "ALTER TABLE x AUTO_INCREMENT=y in SP crashes server"
Test cases for bugs 4968, 19733, 6895 will be added in 5.0.
Re-execution of CREATE DATABASE, CREATE TABLE and ALTER TABLE
statements in stored routines or as prepared statements caused
incorrect results (and crashes in versions prior to 5.0.25).
In 5.1 the problem occured only for CREATE DATABASE, CREATE TABLE
SELECT and CREATE TABLE with INDEX/DATA DIRECTOY options).
The problem of bugs 4968, 19733, 19282 and 6895 was that functions
mysql_prepare_table, mysql_create_table and mysql_alter_table were not
re-execution friendly: during their operation they used to modify contents
of LEX (members create_info, alter_info, key_list, create_list),
thus making the LEX unusable for the next execution.
In particular, these functions removed processed columns and keys from
create_list, key_list and drop_list. Search the code in sql_table.cc
for drop_it.remove() and similar patterns to find evidence.
The fix is to supply to these functions a usable copy of each of the
above structures at every re-execution of an SQL statement.
To simplify memory management, LEX::key_list and LEX::create_list
were added to LEX::alter_info, a fresh copy of which is created for
every execution.
The problem of crashing bug 22060 stemmed from the fact that the above
metnioned functions were not only modifying HA_CREATE_INFO structure in
LEX, but also were changing it to point to areas in volatile memory of
the execution memory root.
The patch solves this problem by creating and using an on-stack
copy of HA_CREATE_INFO (note that code in 5.1 already creates and
uses a copy of this structure in mysql_create_table()/alter_table(),
but this approach didn't work well for CREATE TABLE SELECT statement).
Fixed compiler warnings (detected by VC++):
- Removed not used variables
- Added casts
- Fixed wrong assignments to bool
- Fixed wrong calls with bool arguments
- Added missing argument to store(longlong), which caused wrong store method to be called.
This is a performance issue for queries with subqueries evaluation
of which requires filesort.
Allocation of memory for the sort buffer at each evaluation of a
subquery may take a significant amount of time if the buffer is rather big.
With the fix we allocate the buffer at the first evaluation of the
subquery and reuse it at each subsequent evaluation.
'conc_sys' test
Concurrent execution of SELECT involing at least two INFORMATION_SCHEMA
tables, DROP DATABASE statement and DROP TABLE statement could have
resulted in stalled connection for this SELECT statement.
The problem was that for the first query of a join there was a race
between select from I_S.TABLES and DROP DATABASE, and the error (no
such database) was prepared to be send to the client, but the join
processing was continued. On second query to I_S.COLUMNS there was a
race with DROP TABLE, but this error (no such table) was downgraded to
warning, and thd->net.report_error was reset. And so neither result
nor error was sent to the client.
The solution is to stop join processing once it is clear we are going
to report a error, and also to downgrade to warnings file system errors
like 'no such database' (unless we are in the 'SHOW' command), because
I_S is designed not to use locks and the query to I_S should not abort
if something is dropped in the middle.
No test case is provided since this bug is a result of a race, and is
timing dependant. But we test that plain SHOW TABLES and SHOW COLUMNS
give a error if there is no such database or a table respectively.
Fix for BUG#16676: Database CHARSET not used for stored procedures
The problem in BUG#16211 is that CHARSET-clause of the return type for
stored functions is just ignored.
The problem in BUG#16676 is that if character set is not explicitly
specified for sp-variable, the server character set is used instead
of the database one.
The fix has two parts:
- always store CHARSET-clause of the return type along with the
type definition in mysql.proc.returns column. "Always" means that
CHARSET-clause is appended even if it has not been explicitly
specified in CREATE FUNCTION statement (this affects BUG#16211 only).
Storing CHARSET-clause if it is not specified is essential to avoid
changing character set if the database character set is altered in
the future.
NOTE: this change is not backward compatible with the previous releases.
- use database default character set if CHARSET-clause is not explicitly
specified (this affects both BUG#16211 and BUG#16676).
NOTE: this also breaks backward compatibility.
The fix is: if user has privileges to view fields and user has any
(insert,select,delete,update) privileges on underlying view
then 'show fields' and select from I_S.COLUMNS table are sucsessful.
a non-correlated single-row subquery over information schema.
The function get_all_tables filling all information schema
tables reset lex->sql_command to SQLCOM_SHOW_FIELDS. After
this the function could evaluate partial conditions related to
some columns. If these conditions contained a subquery over
information schema it led to a wrong evaluation and a wrong
result set.
This bug was already fixed in 5.1.
This patch follows the way how it was done in 5.1 where
the value of lex->sql_command is set to SQLCOM_SHOW_FIELDS
in get_all_tables only for the calls of the function
open_normal_and_derived_tables and is restored after these
calls.
subqueries on information schema that use MIN/MAX aggregation.
Execution of some correlated subqueries may set the value
of null_row to 1 for tables used in the subquery.
If the the subquery is on information schema it causes
rejection of any row for the following executions of
the subquery in the case when an optimization filtering
by some condition is applied.
The fix restores the value of the null_row flag for
each execution of a subquery on information schema.
Table comment: issue a warning(error in traditional mode) if length of comment > 60 symbols
Column comment: issue a warning(error in traditional mode) if length of comment > 255 symbols
Table 'comment' is changed from char* to LEX_STRING
After view onening real view db name and table name are placed
into table_list->view_db & table_list->view_name.
Item_field class does not handle these names properly during
intialization of Send_field.
The fix is to use new class 'Item_ident_for_show'
which sets correct view db name and table name for Send_field.
fix: return db name for I_S.TABLES(and others) in original letter case.
if mysql starts with lower_case_table_names=1 | 2 then original db name is converted
to lower case(for I_S tables). It happens when we perform add_table_to_list.
to avoid this we make a copy of original db name and use the copy hereafter.
Bug#18282 "INFORMATION_SCHEMA.TABLES provides inconsistent info about invalid views"
This bug caused crashes or resulted in wrong data being returned
when one tried to obtain information from I_S tables about views
using stored functions.
It was caused by the fact that we were using LEX representing
statement which were doing select from I_S tables as active LEX
when contents of I_S table were built. So state of this LEX both
affected and was affected by open_tables() calls which happened
during this process. This resulted in wrong behavior and in
violations of some of invariants which caused crashes.
This fix tries to solve this problem by properly saving/resetting
and restoring part of LEX which affects and is affected by the
process of opening tables and views in get_all_tables() routine.
To simplify things we separated this part of LEX in a new class
and made LEX its descendant.
mysqldump / SHOW CREATE TABLE will show the NEXT available value for
the PK, rather than the *first* one that was available (that named in
the original CREATE TABLE ... AUTO_INCREMENT = ... statement).
This should produce correct and robust behaviour for the obvious use
cases -- when no data were inserted, then we'll produce a statement
featuring the same value the original CREATE TABLE had; if we dump
with values, INSERTing the values on the target machine should set the
correct next_ID anyway (and if not, we'll still have our AUTO_INCREMENT =
... to do that). Lastly, just the CREATE statement (with no data) for
a table that saw inserts would still result in a table that new values
could safely be inserted to).
There seems to be no robust way however to see whether the next_ID
field is > 1 because it was set to something else with CREATE TABLE
... AUTO_INCREMENT = ..., or because there is an AUTO_INCREMENT column
in the table (but no initial value was set with AUTO_INCREMENT = ...)
and then one or more rows were INSERTed, counting up next_ID. This
means that in both cases, we'll generate an AUTO_INCREMENT =
... clause in SHOW CREATE TABLE / mysqldump. As we also show info on,
say, charsets even if the user did not explicitly give that info in
their own CREATE TABLE, this shouldn't be an issue.
As per above, the next_ID will be affected by any INSERTs that have
taken place, though. This /should/ result in correct and robust
behaviour, but it may look non-intuitive to some users if they CREATE
TABLE ... AUTO_INCREMENT = 1000 and later (after some INSERTs) have
SHOW CREATE TABLE give them a different value (say, CREATE TABLE
... AUTO_INCREMENT = 1006), so the docs should possibly feature a
caveat to that effect.
It's not very intuitive the way it works now (with the fix), but it's
*correct*. We're not storing the original value anyway, if we wanted
that, we'd have to change on-disk representation?
If we do dump/load cycles with empty DBs, nothing will change. This
changeset includes an additional test case that proves that tables
with rows will create the same next_ID for AUTO_INCREMENT = ... across
dump/restore cycles.
Confirmed by support as likely solution for client's problem.
Crash happened when one selected data from one of INFORMATION_SCHEMA
tables and in order to build its contents server had to open view which
used stored function and table or view on which one had not global or
database-level privileges (e.g. had only table-level or had no
privileges at all).
The crash was caused by usage of check_grant() function, which assumes
that either number of tables to be inspected by it is limited explicitly
or table list used and thd->lex->query_tables_own_last value correspond
to each other (the latter should be either 0 or point to next_global
member of one of elements of this table list), in conditions when
above assumptions were not true. This fix just explicitly limits
number of tables to be inspected. Other negative effects which are
caused by the fact that thd->lex->query_tables_own_last might not
be set properly during processing of I_S tables are less disastrous
and will be reported and fixed separetely.
