ORDER BY computed col
GROUP BY implies ORDER BY in the MySQL dialect of SQL. Therefore, when an
index on the first table in the query is used, and that index satisfies
ordering according to the GROUP BY clause, the query optimizer estimates the
number of tuples that need to be read from this index. If there is a LIMIT
clause, table statistics on tables following this 'sort table' are employed.
There may be a separate ORDER BY clause however, which mandates reading the
whole 'sort table' anyway. But the previous estimate was left untouched.
Fixed by removing the estimate from EXPLAIN output if GROUP BY is used in
conjunction with an ORDER BY clause that mandates using a temporary table.
The problem could be demonstrated with an outer join of two single-row
tables where the values of the join attributes were null. Any query
with such a join could return a wrong result set if the where
condition of the query was not empty. For queries with empty
where conditions the result sets were correct.
This was the consequence of two bugs in the code:
- Item_equal objects for on conditions of outer joins were
not built if the processed query had no where condition
- the check for null values in the code that evaluated constant
Item_equal objects was incorrect.
Fixed both above problems.
Added a test case for the bug and adjusted results for some other
test cases.
When not-exists optimization was applied to a table that
happened to be an inner table of two outer joins, one
embedded into another, then setting the match flag for
the embedding outer join on could be skipped. This caused
generation of extra null complemented rows.
Made sure that the match flags are set correctly in all cases
when not-exists optimization is used.
inited==INDEX
When an error occurs while sending the data in a temporary table there was no
cleanup performed. This caused a failed assertion in the case when different
access methods were used for populating the table vs. retrieving the data from
the table if IGNORE was specified and sql_safe_updates = 0. In this case
execution continues, but the handler expects to continue with the access
method used for row retrieval.
Fixed by doing the cleanup even if errors occur.
Fall back to use ALTER TABLE for engines that doesn't support REPAIR when doing repair for upgrade.
Nicer output from mysql_upgrade and mysql_check
Updated all arrays that used NAME_LEN to use SAFE_NAME_LEN to ensure that we don't break things accidently as names can now have a #mysql50# prefix.
client/mysql_upgrade.c:
If we are using verbose, also run mysqlcheck in verbose mode.
client/mysqlcheck.c:
Add more information if running in verbose mode
Print 'Needs upgrade' instead of complex error if table needs to be upgraded
Don't write connect information if verbose is not 2 or above
mysql-test/r/drop.result:
Updated test and results as we now support full table names
mysql-test/r/grant.result:
Now you get a correct error message if using #mysql with paths
mysql-test/r/show_check.result:
Update results as table names can temporarly be bigger than NAME_LEN (during upgrade)
mysql-test/r/upgrade.result:
Test upgrade for long table names.
mysql-test/suite/funcs_1/r/is_tables_is.result:
Updated old test result (had note been updated in a while)
mysql-test/t/drop.test:
Updated test and results as we now support full table names
mysql-test/t/grant.test:
Now you get a correct error message if using #mysql with paths
mysql-test/t/upgrade.test:
Test upgrade for long table names.
sql/ha_partition.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/item.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/log_event.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/mysql_priv.h:
Added SAFE_NAME_LEN
sql/rpl_filter.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sp.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sp_head.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_acl.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_base.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_connect.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_parse.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_prepare.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_select.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_show.cc:
NAME_LEN -> SAFE_NAME_LEN
Enlarge table names for SHOW TABLES to also include optional #mysql50#
sql/sql_table.cc:
Fall back to use ALTER TABLE for engines that doesn't support REPAIR when doing repair for upgrade.
sql/sql_trigger.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_udf.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/sql_view.cc:
NAME_LEN -> SAFE_NAME_LEN
sql/table.cc:
Fixed check_table_name() to not count #mysql50# as part of name
If #mysql50# is part of the name, don't allow path characters in name.
- Changed to still use bcmp() in certain cases becasue
- Faster for short unaligneed strings than memcmp()
- Bettern when using valgrind
- Changed to use my_sprintf() instead of sprintf() to get higher portability for old systems
- Changed code to use MariaDB version of select->skip_record()
- Removed -%::SCCS/s.% from Makefile.am:s to remove automake warnings
Bug#46754: 'rows' field doesn't reflect partition pruning
The EXPLAIN's result in 'rows' field
was evaluated to number of rows when the table was opened
(not from the table cache) and only the partitions left
after pruning was updated with its correct number
of rows.
The evaluation of the 'rows' field was using handler::records()
which is a potentially expensive call, and ignores the partitioning
pruning.
The fix was to use the handlers stats.records after updating it
with ::info(HA_STATUS_VARIABLE) instead.
mysql-test/r/partition_pruning.result:
updated result
mysql-test/t/partition_pruning.test:
Added test.
sql/sql_select.cc:
Use ::info + stats.records instead of ::records().
called twice in a row
Queries with nested joins could cause an infinite loop in the
server when used from SP/PS.
When flattening nested joins, simplify_joins() tracks if the
name resolution list needs to be updated by setting
fix_name_res to TRUE if the current loop iteration has done any
transformations to the join table list. The problem was that
the flag was not reset before the next loop iteration leading
to unnecessary "fixing" of the name resolution list which in
turn could lead to a loop (i.e. circularly-linked part) in that
list. This was causing problems on subsequent execution when
used together with stored procedures or prepared statements.
Fixed by making sure fix_name_res is reset on every loop
iteration.
mysql-test/r/join.result:
Added a test case for bug #53544.
mysql-test/t/join.test:
Added a test case for bug #53544.
sql/sql_select.cc:
Make sure fix_name_res is reset on every loop iteration.
After fix for bug 39653 the shortest available secondary index was used for
full table scan. Primary clustered key was used only if no secondary index
can be used. However, when chosen secondary index includes all fields of the
table being scanned it's better to use primary index since the amount of
data to scan is the same but the primary index is clustered.
Now the find_shortest_key function takes this into account.
mysql-test/suite/innodb/r/innodb_mysql.result:
Added a test case for the bug#55656.
mysql-test/suite/innodb/t/innodb_mysql.test:
Added a test case for the bug#55656.
sql/sql_select.cc:
Bug #55656: mysqldump can be slower after bug #39653 fix.
The find_shortest_key function now prefers clustered primary key
if found secondary key includes all fields of the table.
within query
The server could crash after materializing a derived table
which requires a temporary table for grouping.
When destroying the temporary table used to execute a query for
a derived table, JOIN::destroy() did not clean up Item_fields
pointing to fields in the temporary table. This led to
dereferencing a dangling pointer when printing out the items
tree later in the outer SELECT.
The solution is an addendum to the patch for bug37362: in
addition to cleaning up items in tmp_all_fields3, do the same
for items in tmp_all_fields1, since now we have an example
where this is necessary.
mysql-test/r/join.result:
Added test cases for bug#55568 and a duplicate bug #54468.
mysql-test/t/join.test:
Added test cases for bug#55568 and a duplicate bug #54468.
sql/field.cc:
Make sure field->table_name is not set to NULL in
Field::make_field() to avoid assertion failure in
Item_field::make_field() after cleaning up items
(the assertion fired in udf.test when running
the test suite with the patch applied).
sql/sql_select.cc:
In addition to cleaning up items in tmp_all_fields3, do the
same for items in tmp_all_fields1.
Introduce a new helper function to avoid code duplication.
sql/sql_select.h:
Introduce a new helper function to avoid code duplication in
JOIN::destroy().
mysql-test/r/group_by.result:
Added test that showed problems that no_rows_in_results() didn't work for expressions
mysql-test/r/subselect4.result:
Test case for LP#612894
mysql-test/t/group_by.test:
Added test that showed problems that no_rows_in_results() didn't work for expressions
mysql-test/t/subselect4.test:
Test case for LP#612894
sql/item.h:
Added restore_to_before_no_rows_in_result()
Added function processor for no_rows_in_results() and restore_to_before_no_rows_in_results() to ensure it works with functions
Fix that above functions are handled by Item_ref()
sql/item_func.h:
Ensure that no_rows_in_results() and restore_to_before_no_rows_in_result() are called for all function arguments
sql/item_sum.cc:
Added restore_to_before_no_rows_in_result() to restore settings after Item_sum_hybrid::no_rows_in_result() was called.
This is needed to handle the case where we have made 'make_const()' on the item in opt_sum(), but the item will be reused again in a sub query.
Ignore multiple calls to no_rows_in_result() as Item_ref is calling it twice.
sql/item_sum.h:
Added restore_to_before_no_rows_in_result();
sql/sql_select.cc:
Added reset of no_rows_in_result() for JOIN::reinit()
sql/sql_select.h:
Added marker if no_rows_in_result() is called.
The server was not checking for errors generated during
the execution of Item::val_xxx() methods when copying
data to the group, order, or distinct temp table's row.
Fixed by extending the copy_funcs() to return an error
code and by checking for that error code on the places
copy_funcs() is called.
Test case added.
INSERT IGNORE ... SELECT ... UNION SELECT ...
This assert was triggered by INSERT IGNORE ... SELECT. The assert checks that a
statement either sends OK or an error to the client. If the bug was triggered
on release builds, it caused OK to be sent to the client instead of the correct
error message (in this case ER_FIELD_SPECIFIED_TWICE).
The reason the assert was triggered, was that lex->no_error was set to TRUE
during JOIN::optimize() because of IGNORE. This causes all errors to be ignored.
However, not all errors can be ignored. Some, such as ER_FIELD_SPECIFIED_TWICE
will cause the INSERT to fail no matter what. But since lex->no_error was set,
the critical errors were ignored, the INSERT failed and neither OK nor the
error message was sent to the client.
This patch fixes the problem by temporarily turning off lex->no_error in
places where errors cannot be ignored during processing of INSERT ... SELECT.
Test case added to insert.test.
Changed to use longlong10_to_str() instead of longlong2str() when base is 10 or -10 as former is much faster than later
Changed my_vsnprintf() to use longlong2str instead of int2str() to get rid of warnings and to get support for long pointers even when long is 32 bit.
client/mysqltest.cc:
longlong2str() -> longlong10_to_str()
include/m_string.h:
Added extra argument to longlong2str() to make it have same prototype is int2str()
mysys/charset.c:
Fixed compiler warning
mysys/mf_soundex.c:
Fixed compiler warning
mysys/my_getopt.c:
longlong2str() -> longlong10_to_str()
sql/create_options.cc:
Fixed compiler warning
sql/item_strfunc.cc:
Added extra argument to longlong2str
sql/opt_range.cc:
longlong2str() -> longlong10_to_str()
sql/partition_info.cc:
longlong2str() -> longlong10_to_str()
sql/slave.cc:
longlong2str() -> longlong10_to_str()
sql/sql_bitmap.h:
Added extra argument to longlong2str
sql/sql_partition.cc:
Added extra argument to longlong2str
sql/sql_select.cc:
longlong2str() -> longlong10_to_str()
sql/sql_show.cc:
Added extra argument to longlong2str
storage/innodb_plugin/handler/ha_innodb.cc:
Update to new parameters for longlong2str()
storage/maria/ma_dbug.c:
longlong2str() -> longlong10_to_str()
storage/maria/maria_chk.c:
Added extra argument to longlong2str
storage/myisam/mi_dbug.c:
longlong2str() -> longlong10_to_str()
storage/myisam/myisamchk.c:
Added extra argument to longlong2str
storage/xtradb/handler/ha_innodb.cc:
Update to new parameters for longlong2str()
strings/longlong2str.c:
Added extra argument to longlong2str() to make it have same prototype is int2str()
strings/my_vsnprintf.c:
Changed my_vsnprintf() to use longlong2str instead of int2str() to get rid of warnings and to get support for long pointers even when long is 32 bit.
Added cast to get rid of compiler warnings
This was triggered by innodb.innodb_multi_update, where we had a static length row without nulls and xtradb didn't fill in the delete-marker byte
include/my_bitmap.h:
Added prototype for bitmap_union_is_set_all()
mysys/my_bitmap.c:
Added function to check if union of two bit maps covers all bits.
sql/mysql_priv.h:
Updated protype for compare_record()
sql/sql_insert.cc:
Send to compare_record() flag if all fields are used.
sql/sql_select.cc:
Set share->null_bytes_for_compare.
sql/sql_update.cc:
In compare_record() don't use the fast cmp_record() (which is basically memcmp) if we don't know that all fields exists.
Don't compare the null_bytes if there is no data there.
sql/table.cc:
Store in share->null_bytes_for_compare the number of bytes that has null or bit fields (but not delete marker)
Store in can_cmp_whole_record if we can use memcmp() (assuming all rows are read) to compare rows in compare_record()
sql/table.h:
Added two elements in table->share to speed up checking how updated rows can be compared.
check_join_cache_usage() by the change:
Revno: 2793
Revision Id: igor@askmonty.org-20091221022615-kx5ieiu0okmiupuc
Timestamp: Sun 2009-12-20 18:26:15 -0800
Backport into MariaDB-5.2 the following:
WL#2771 "Block Nested Loop Join and Batched Key Access Join"
For queries with order by clauses that employed filesort usage of
virtual column references in select lists could trigger assertion
failures. It happened because a wrong vcol_set bitmap was used for
filesort. It turned out that filesort required its own vcol_set bitmap.
Made management of the vcol_set bitmaps similar to the management
of the read_set and write_set bitmaps.
This assert checks that the server does not try to send OK to the
client if there has been some error during processing. This is done
to make sure that the error is in fact sent to the client.
The problem was that view errors during processing of WHERE conditions
in UPDATE statements where not detected by the update code. It therefore
tried to send OK to the client, triggering the assert.
The bug was only noticeable in debug builds.
This patch fixes the problem by making sure that the update code
checks for errors during condition processing and acts accordingly.
If the expression for a virtual column of table contained datetime
comparison then the execution of the second query that used this
virtual column caused a crash. It happened because the execution
of the first query that used this virtual column inserted a cached
item into the expression tree. The cached tree was allocated in
the statement memory while the expression tree was allocated in
the table memory.
Now the cached items that are inserted into expressions for virtual
columns with datetime comparisons are always allocated in the same
mem_root as the expressions for virtual columns. So now the inserted
cached items are valid for any queries that use these virtual columns.
The issue was that we didn't always check result of ha_rnd_init() which caused a problem for handlers that returned an error in this code.
- Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked.
- Added ha_rnd_init_with_error() that prints error on failure.
- Checked all usage of ha_rnd_init() and ensure we generate an error message on failures.
- Changed init_read_record() to return 1 on failure.
sql/create_options.cc:
Fixed wrong printf
sql/event_db_repository.cc:
Check result from init_read_record()
sql/events.cc:
Check result from init_read_record()
sql/filesort.cc:
Check result from ha_rnd_init()
sql/ha_partition.cc:
Check result from ha_rnd_init()
sql/ha_partition.h:
Fixed compiler warning
sql/handler.cc:
Added ha_rnd_init_with_error()
Check result from ha_rnd_init()
sql/handler.h:
Added ha_rnd_init_with_error()
Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked
sql/item_subselect.cc:
Check result from ha_rnd_init()
sql/log.cc:
Check result from ha_rnd_init()
sql/log_event.cc:
Check result from ha_rnd_init()
sql/log_event_old.cc:
Check result from ha_rnd_init()
sql/mysql_priv.h:
init_read_record() now returns error code on failure
sql/opt_range.cc:
Check result from ha_rnd_init()
sql/records.cc:
init_read_record() now returns error code on failure
Check result from ha_rnd_init()
sql/sql_acl.cc:
Check result from init_read_record()
sql/sql_cursor.cc:
Print error if ha_rnd_init() fails
sql/sql_delete.cc:
Check result from init_read_record()
sql/sql_help.cc:
Check result from init_read_record()
sql/sql_plugin.cc:
Check result from init_read_record()
sql/sql_select.cc:
Check result from ha_rnd_init()
Print error if ha_rnd_init() fails.
sql/sql_servers.cc:
Check result from init_read_record()
sql/sql_table.cc:
Check result from init_read_record()
sql/sql_udf.cc:
Check result from init_read_record()
sql/sql_update.cc:
Check result from init_read_record()
storage/example/ha_example.cc:
Don't return error on rnd_init()
storage/ibmdb2i/ha_ibmdb2i.cc:
Removed not relevant comment
1. Changed the lazy optimization for subqueries that can be
materialized into bottom-up optimization during the optimization of
the main query.
The main change is implemented by the method
Item_in_subselect::setup_engine.
All other changes were required to correct problems resulting from
changing the order of optimization. Most of these problems followed
the same pattern - there are some shared structures between a
subquery and its parent query. Depending on which one is optimized
first (parent or child query), these shared strucutres may get
different values, thus resulting in an inconsistent query plan.
2. Changed the code-generation for subquery materialization to be
performed in runtime memory for each (re)execution, instead of in
statement memory (once per prepared statement).
- Item_in_subselect::setup_engine() no longer creates materialization
related objects in statement memory.
- Merged subselect_hash_sj_engine::init_permanent and
subselect_hash_sj_engine::init_runtime into
subselect_hash_sj_engine::init, which is called for each
(re)execution.
- Fixed deletion of the temp table accordingly.
mysql-test/r/subselect_mat.result:
Adjusted changed EXPLAIN because of earlier optimization of subqueries.
subquery execution, where the the REF buffer format was mistaken to
be in record format instead of key format. The error was that the null
byte for all fields of the record was in the front of the buffer,
and not before each field data.
libmysqld/Makefile.am:
The new file added.
mysql-test/r/index_merge_myisam.result:
subquery_cache optimization option added.
mysql-test/r/myisam_mrr.result:
subquery_cache optimization option added.
mysql-test/r/subquery_cache.result:
The subquery cache tests added.
mysql-test/r/subselect3.result:
Subquery cache switched off to avoid changing read statistics.
mysql-test/r/subselect3_jcl6.result:
Subquery cache switched off to avoid changing read statistics.
mysql-test/r/subselect_no_mat.result:
subquery_cache optimization option added.
mysql-test/r/subselect_no_opts.result:
subquery_cache optimization option added.
mysql-test/r/subselect_no_semijoin.result:
subquery_cache optimization option added.
mysql-test/r/subselect_sj.result:
subquery_cache optimization option added.
mysql-test/r/subselect_sj_jcl6.result:
subquery_cache optimization option added.
mysql-test/t/subquery_cache.test:
The subquery cache tests added.
mysql-test/t/subselect3.test:
Subquery cache switched off to avoid changing read statistics.
sql/CMakeLists.txt:
The new file added.
sql/Makefile.am:
The new files added.
sql/item.cc:
Expression cache item (Item_cache_wrapper) added.
Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP.
sql/item.h:
Expression cache item (Item_cache_wrapper) added.
Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP.
sql/item_cmpfunc.cc:
Subquery cache added.
sql/item_cmpfunc.h:
Subquery cache added.
sql/item_subselect.cc:
Subquery cache added.
sql/item_subselect.h:
Subquery cache added.
sql/item_sum.cc:
Registration of subquery parameters added.
sql/mysql_priv.h:
subquery_cache optimization option added.
sql/mysqld.cc:
subquery_cache optimization option added.
sql/opt_range.cc:
Fix due to subquery cache.
sql/opt_subselect.cc:
Parameters of the function cahnged.
sql/procedure.h:
.h file guard added.
sql/sql_base.cc:
Registration of subquery parameters added.
sql/sql_class.cc:
Option to allow add indeces to temporary table.
sql/sql_class.h:
Item iterators added.
Option to allow add indeces to temporary table.
sql/sql_expression_cache.cc:
Expression cache for caching subqueries added.
sql/sql_expression_cache.h:
Expression cache for caching subqueries added.
sql/sql_lex.cc:
Registration of subquery parameters added.
sql/sql_lex.h:
Registration of subqueries and subquery parameters added.
sql/sql_select.cc:
Subquery cache added.
sql/sql_select.h:
Subquery cache added.
sql/sql_union.cc:
A new parameter to the function added.
sql/sql_update.cc:
A new parameter to the function added.
sql/table.cc:
Procedures to manage temporarty tables index added.
sql/table.h:
Procedures to manage temporarty tables index added.
storage/maria/ha_maria.cc:
Fix of handler to allow destoy a table in case of error during the table creation.
storage/maria/ha_maria.h:
.h file guard added.
storage/myisam/ha_myisam.cc:
Fix of handler to allow destoy a table in case of error during the table creation.
- Item_in_subselect::init_left_expr_cache() should not try to
guess whether the left expression is accessed "over the grouping operation"
(i.e. the subselect is evaluated after the grouping while the left_expr is
an Item_ref that wraps an expression from before the grouping). Instead,
let new_Cached_item not to try accessing item->real_item() when creating
left expr cache.
The problem is that QUICK_SELECT_DESC behaviour depends
on used_key_parts value which can be bigger than selected
best_key_parts value if an engine supports clustered key.
But used_key_parts is overwritten with best_key_parts
value that prevents from correct selection of index
access method. The fix is to preserve used_key_parts
value for further use in QUICK_SELECT_DESC.
mysql-test/r/innodb_mysql.result:
test case
mysql-test/t/innodb_mysql.test:
test case
sql/sql_select.cc:
preserve used_key_parts value for further use in QUICK_SELECT_DESC
- fix a bug in LooseScan strategy execution code (exposed by changing costs/QEP)
- Do set join_tab->sorted=TRUE for JOIN_TABs that use LooseScan (partitioning
handler cares about "sorted" parameter of h->index_init() call)
file .\filesort.cc, line 149 (part II)
Problem: the server didn't disregard sort order
for some zero length tuples.
Fix: skip sort order in such a case
(zero length NOT NULL string functions).
mysql-test/r/select.result:
Fix for bug #54459: Assertion failed: param.sort_length,
file .\filesort.cc, line 149 (part II)
- test result.
mysql-test/t/select.test:
Fix for bug #54459: Assertion failed: param.sort_length,
file .\filesort.cc, line 149 (part II)
- test case.
sql/sql_select.cc:
Fix for bug #54459: Assertion failed: param.sort_length,
file .\filesort.cc, line 149 (part II)
- disregard sort order for zero length NOT NULL string functions
along with zero length NOT NULL fields.
The problem there is that HAVING condition evaluates const
parts of condition despite the condition has references
on aggregate functions. Table t1 became const tables
after make_join_statistics and table1.pk = 1, HAVING is
transformed into MAX(1) < 7 and taken away from HAVING.
The fix is to skip evaluation of HAVING conts parts if
HAVING condition has references on aggregate functions.
mysql-test/r/having.result:
test case
mysql-test/t/having.test:
test case
sql/sql_select.cc:
skip evaluation of HAVING conts parts if
HAVING condition has references on aggregate functions.
