In this case we are setting the field Item_func_eq::in_eqaulity_no for the semi-join equalities.
This helps us to remove these equalites as the inner tables are not available during parent select execution
while the outer tables are not available during materialization phase.
We only have it set for the equalites for the fields involved with the IN subquery
and reset it for the equalities which do not belong to the IN subquery.
For example in case of nested IN subqueries:
SELECT t1.a FROM t1 WHERE t1.a IN
(SELECT t2.a FROM t2 where t2.b IN
(select t3.b from t3 where t3.c=27 ))
there are two equalites involving the fields of the IN subquery
1) t2.b = t3.b : the field Item_func_eq::in_eqaulity_no is set when we merge the grandchild select into the child select
2) t1.a = t2.a : the field Item_func_eq::in_eqaulity_no is set when we merge the child select into the parent select
But when we perform case 2) we should ensure that we reset the equalities in the child's WHERE clause.
with join_cache_level>2
During muliple equality propagation for a query in which we have an IN subquery, the items in the select list of the
subquery may not be part of the multiple equality because there might be another occurence of the same field in the
where clause of the subquery.
So we keyuse_is_valid_for_access_in_chosen_plan function which expects the items in the select list of the subquery to
be same to the ones in the multiple equality (through these multiple equalities we create keyuse array).
The solution would be that we expect the same field not the same Item because when we have SEMI JOIN MATERIALIZATION SCAN,
we use copy back technique to copies back the materialised table fields to the original fields of the base tables.
This patch fixes another problem introduced by the patch for mdev-4817.
The latter changed Item_cond::fix_fields() in such a way that it could
call the virtual method is_expensive(). With the first its call
the method saves the result in Item::is_expensive_cache. For all next
calls the method returns the result from this cache. So if the item
once was determined as expensive the method always returns true.
For subqueries it's not good, because non-optimized subqueries always
is considered as expensive.
It means that the cache should be invalidated after the call of
optimize_constant_subqueries().
This patch fixes another problem introduced by the patch for mdev-4817.
The latter changed Item_cond::fix_fields() in such a way that it could
call the virtual method is_expensive(). With the first its call
the method saves the result in Item::is_expensive_cache. For all next
calls the method returns the result from this cache. So if the item
once was determined as expensive the method always returns true.
For subqueries it's not good, because non-optimized subqueries always
is considered as expensive.
It means that the cache should be invalidated after the call of
optimize_constant_subqueries().
In Galera BF (brute force) transactions may not wait for lock requests
and normally BF-transaction would select transaction holding conflicting
locks as a victim for rollback. However, background statistic calculation
transaction is InnoDB internal transaction and it has no thd i.e. it can't be
selected as a victim. If background statistics calculation transaction holds
conflicting locks to statistics tables it will cause BF lock wait long
error message. Correct way to handle background statistics calculation is to
acquire thd for transaction but that change is too big for GA-releases and
there are other reported problems on background statistics calculation.
This fix avoids adding a table to background statistics calculation if
This patch fixes another problem introduced by the patch for mdev-4817.
The latter changed Item_cond::fix_fields() in such a way that it could
call the virtual method is_expensive(). With the first its call
the method saves the result in Item::is_expensive_cache. For all next
calls the method returns the result from this cache. So if the item
once was determined as expensive the method always returns true.
For subqueries it's not good, because non-optimized subqueries always
is considered as expensive.
It means that the cache should be invalidated after the call of
optimize_constant_subqueries().
Due to a legacy bug in the code of make_join_statistics() detecting
so-called constant tables could miss some of them in rare queries
that used RIGHT JOIN. As a result these queries had execution plans
different from the execution plans of the equivalent queries with
LEFT JOIN.
Besides starting from 10.2 this could trigger an assertion failure.
Restricted output for CREATE USER, GRANT, REVOKE and SET PASSWORD
so that it shows only above keywords but not rest of query i.e.
not user or password.
avoid round-robin conversions, if the column is MODIFY-ed,
it should always be modified to its final definition, not to some
intermediate state.
also avoid other unconditional changes, like
ALTER TABLE event DROP PRIMARY KEY;
ALTER TABLE event ADD PRIMARY KEY(db, name);
don't try to set default time zone in --bootstrap,
this generally cannot be done, as timezone tables aren't loaded.
and bootstrap scripts don't need it anyway.
Don't install server files if WITHOUT_SERVER is specified.
"Server files" are defined as files going into the MariaDB-Server RPM,
that is files in the components Server, ManPagesServer, Server_Scripts,
IniFiles, SuportFiles, and Readme.
MEMORY table could be renamed into a non-extistent database.
rename() is documented to return ENOENT when the source file does not
exist OR when the target directory not exist. Nonexistent source .frm
file is ok (table can still exist in the engine), nonexistent target
directory is not.
Make my_rename to use ENOTDIR for the latter case. Make RENAME TABLE
issue an appropriate error ("unknown database" instead of "unknown table")
snprintf returns the number of bytes it wrote (or would have written) NOT
counting the \0 terminal character.
The buffer size it accepts as argument DOES COUNT the \0 character.
Pass the right parameter value.
After the MDEV-13118 fix there's no code in the server that
wants caseup/casedn to change the argument in place for simple
charsets. Let's remove this logic and always return the result in a
new string for all charsets, both simple and complex.
1. Removing the optimization that *some* character sets used in casedn()
and caseup(), which allowed (and required) to change the case in-place,
overwriting the string passed as the "src" argument.
Now all CHARSET_INFO's work in the same way:
non of them change the source string in-place, all of them now convert
case from the source string to the destination string, leaving
the source string untouched.
2. Adding "const" qualifier to the "char *src" parameter
to caseup() and casedn().
3. Removing duplicate implementations in ctype-mb.c.
Now both caseup() and casedn() implementations for all CJK character sets
use internally the same function my_casefold_mb()
(the former my_casefold_mb_varlen()).
4. Removing the "unused" attribute from parameters of some my_case{up|dn}_xxx()
implementations, as the affected parameters are now *used* in the code.
Previously these parameters were used only in DBUG_ASSERT().
This problem is similar to MDEV-10306.
1. Fixing Item_str_conv::val_str(String *str) to return the result in "str",
and to use tmp_value only as a temporary buffer for args[0]->val_str().
The new code version now guarantees that the result is always returned in
"str". The trick with copy_if_not_alloced() is not used any more.
2. The change #1 revealed the same problem in SUBSTRING_INDEX(),
so some tests with combinations of UPPER()/LOWER() and SUBSTRING_INDEX()
started to fail. Fixing Item_func_substr_index::val_str() the same way,
to return the result in "str" and use tmp_value as a temporary buffer
for args[0]->val_str().
Problem:- Create/drop index was logged into binlog.
Goal:- Operation on temporary table should not be binlog when binlog format
is row.
Solution:-
We should add CF_FORCE_ORIGINAL_BINLOG_FORMAT when there is ddl on temp
table.
For optimize, analyze, repair we wont change anything ,Then will
be logged in binlog , But they also dont throw any error if operation fails
Since slave wont be having any temp table , but these operation on tmp
table will be processed without breaking replication.
For rename we need a different logic MDEV-16728 will solve it.
for the small InnoDB table
This bug was introduced by the patch 6c414fcf89.
The patch has not taken into account that some objects of the Field_* types
are created only for TABLE_SHARE and the field 'table' is set to NULL
for them. In particular such are objects created to store statistical
min/max values for columns.
for blob column
ANALYZE TABLE <table> does not collect statistical data on min/max values
for BLOB columns of <table>. However these values can be added into
mysql.column_stats manually by executing proper statements.
Unfortunately this led to a memory leak because the memory allocated
for these values was never freed.
This patch provides the server with a function to free memory allocated
for min/max statistical values of BLOB types.
Temporarily changed the test case until MDEV-16711 is fixed as without
this fix the test case for MDEV-16757 did not fail only for 10.0.
for blob column
ANALYZE TABLE <table> does not collect statistical data on min/max values
for BLOB columns of <table>. However these values can be added into
mysql.column_stats manually by executing proper statements.
Unfortunately this led to a memory leak because the memory allocated
for these values was never freed.
This patch provides the server with a function to free memory allocated
for min/max statistical values of BLOB types.
Backport the fix f214d36512 to 10.0
Author: Sergei Golubchik <serg@mariadb.org>
Date: Tue Apr 17 00:44:34 2018 +0200
ASAN error in is_stat_table()
don't memcmp beyond the first argument's end
Also: use my_strcasecmp(table_alias_charset), like elsewhere, not memcmp
In this issue we are using derived_with_keys optimization and we are using these keys to do a hash join which is incorrect.
We cannot create keys for dervied tables whose keyparts have types are of BLOB or TEXT type. TEXT or BLOB columns can only be
indexed over a specified length.
Disks with native 4K sectors need 4K alignment and size for unbuffered IO
(i.e for files opened with FILE_FLAG_NO_BUFFERING)
Innodb opens redo log with FILE_FLAG_NO_BUFFERING, however it always does
512byte IOs. Thus, the IO on 4K native sectors will fail, rendering
Innodb non-functional.
The fix is to check whether OS_FILE_LOG_BLOCK_SIZE is multiple of logical
sector size, and if it is not, reopen the redo log without
FILE_FLAG_NO_BUFFERING flag.
"my_snprintf(NULL, 0, ...)" does not follow what snprintf does. Change
the call in wsrep_dump_rbr_buf_with_header to use snprintf (note that
wsrep_dump_rbr_buf was using snprintf all the way).
Fix an off-by-one error in comparison so it actually prints the output
When the definition of the index used for hash join was created
in create_hj_key_for_table() it could cause memory overwrite
due to a bug that led to an underestimation of the number of
the index component.
Change the float comparison function to use a negated version when
comparing for equality. This actually produces less code when compiling
with optimizations (O3) on.
