Details
-
Type:
Technical task
-
Status: Closed
-
Priority:
Major
-
Resolution: Fixed
-
Affects Version/s: None
-
Fix Version/s: 10.0.1
-
Component/s: None
-
Labels:None
Description
#0 0x00000000005c3752 in Item_ref::real_item (this=0x0) at 10.0-exists2in/sql/item.h:2920 2920 Item *real_item() #0 0x00000000005c3752 in Item_ref::real_item (this=0x0) at 10.0-exists2in/sql/item.h:2920 #1 0x00000000005c3793 in Item_ref::real_item (this=0x3908828) at 10.0-exists2in/sql/item.h:2922 ... #8846 0x00000000005c3793 in Item_ref::real_item (this=0x3908828) at 10.0-exists2in/sql/item.h:2922 #8847 0x00000000005c3793 in Item_ref::real_item (this=0x3908828) at 10.0-exists2in/sql/item.h:2922 #8848 0x00000000007fb4a1 in Item_direct_view_ref::replace_equal_field (this=0x3908828, arg=0x7fecfcc6b3c0 "\230\226\220\003") at 10.0-exists2in/sql/item.cc:8051 #8849 0x00000000007f8538 in Item_ref::transform (this=0x3908828, transformer=&virtual Item::replace_equal_field(unsigned char*), arg=0x7fecfcc6b3c0 "\230\226\220\003") at 10.0-exists2in/sql/item.cc:7006 #8850 0x000000000080bb53 in Item_in_optimizer::transform (this=0x3908628, transformer=&virtual table offset 824, argument=0x7fecfcc6b3c0 "\230\226\220\003") at 10.0-exists2in/sql/item_cmpfunc.cc:1837 #8851 0x0000000000814e26 in Item_cond::transform (this=0x3909258, transformer=&virtual table offset 824, arg=0x7fecfcc6b3c0 "\230\226\220\003") at 10.0-exists2in/sql/item_cmpfunc.cc:4456 #8852 0x0000000000832546 in Item_func::transform (this=0x3918098, transformer=&virtual table offset 824, argument=0x7fecfcc6b3c0 "\230\226\220\003") at 10.0-exists2in/sql/item_func.cc:360 #8853 0x0000000000663255 in substitute_for_best_equal_field (context_tab=0x1, cond=0x3918098, cond_equal=0x39030a8, table_join_idx=0x3909fd8) at 10.0-exists2in/sql/sql_select.cc:12490 #8854 0x0000000000662f4c in substitute_for_best_equal_field (context_tab=0x1, cond=0x3902fb8, cond_equal=0x39030a8, table_join_idx=0x3909fd8) at 10.0-exists2in/sql/sql_select.cc:12443 #8855 0x0000000000646a8a in JOIN::optimize_inner (this=0x3905948) at 10.0-exists2in/sql/sql_select.cc:1361 #8856 0x0000000000645414 in JOIN::optimize (this=0x3905948) at 10.0-exists2in/sql/sql_select.cc:994 #8857 0x000000000064d0f2 in mysql_select (thd=0x38cb8a0, rref_pointer_array=0x38cec68, tables=0x38facd8, wild_num=1, fields=..., conds=0x3902fb8, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2147748608, result=0x3914648, unit=0x38ce2c0, select_lex=0x38ce9b8) at 10.0-exists2in/sql/sql_select.cc:3193 #8858 0x000000000064387e in handle_select (thd=0x38cb8a0, lex=0x38ce210, result=0x3914648, setup_tables_done_option=0) at 10.0-exists2in/sql/sql_select.cc:362 #8859 0x000000000061b13b in execute_sqlcom_select (thd=0x38cb8a0, all_tables=0x38facd8) at 10.0-exists2in/sql/sql_parse.cc:4937 #8860 0x00000000006137a8 in mysql_execute_command (thd=0x38cb8a0) at 10.0-exists2in/sql/sql_parse.cc:2421 #8861 0x000000000061d9f6 in mysql_parse (thd=0x38cb8a0, rawbuf=0x3759598 "SELECT * FROM t1, v WHERE NOT EXISTS ( SELECT * FROM t3 WHERE c = b ) AND a = b", length=79, parser_state=0x7fecfcc6c4e0) at 10.0-exists2in/sql/sql_parse.cc:6056 #8862 0x000000000061099a in dispatch_command (command=COM_QUERY, thd=0x38cb8a0, packet=0x38d5ab1 "SELECT * FROM t1, v WHERE NOT EXISTS ( SELECT * FROM t3 WHERE c = b ) AND a = b", packet_length=79) at 10.0-exists2in/sql/sql_parse.cc:1216 #8863 0x000000000060fb93 in do_command (thd=0x38cb8a0) at 10.0-exists2in/sql/sql_parse.cc:945 #8864 0x000000000071a57a in do_handle_one_connection (thd_arg=0x38cb8a0) at 10.0-exists2in/sql/sql_connect.cc:1254 #8865 0x0000000000719f4a in handle_one_connection (arg=0x38cb8a0) at 10.0-exists2in/sql/sql_connect.cc:1168
branch: 10.0-exists2in revision-id: psergey@askmonty.org-20121123063639-1jqbkjuxevqe1vb6 date: 2012-11-23 10:36:39 +0400 revno: 3482
Reproducible with MyISAM, Aria.
Minimal optimizer_switch: in_to_exists=on,exists_to_in=on
Full optimizer_switch (default + exists_to_in=on):
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=off,exists_to_in=on
EXPLAIN causes the same problem.
Test case:
SET optimizer_switch = 'exists_to_in=on'; CREATE TABLE t1 (a INT) ENGINE=MyISAM; INSERT INTO t1 VALUES (1),(7); CREATE TABLE t2 (b INT) ENGINE=MyISAM; INSERT INTO t2 VALUES (8); CREATE ALGORITHM=MERGE VIEW v AS SELECT * FROM t2; CREATE TABLE t3 (c INT) ENGINE=MyISAM; INSERT INTO t3 VALUES (4),(6); SELECT * FROM t1, v WHERE NOT EXISTS ( SELECT * FROM t3 WHERE c = b ) AND a = b;
Variation of the test case (subquery instead of the view):
SET optimizer_switch = 'exists_to_in=on'; CREATE TABLE t1 (a INT) ENGINE=MyISAM; INSERT INTO t1 VALUES (1),(7); CREATE TABLE t2 (b INT) ENGINE=MyISAM; INSERT INTO t2 VALUES (8); CREATE TABLE t3 (c INT) ENGINE=MyISAM; INSERT INTO t3 VALUES (4),(6); SELECT * FROM t1, ( SELECT * FROM t2 ) alias WHERE NOT EXISTS ( SELECT * FROM t3 WHERE c = b ) AND a = b;
Gliffy Diagrams
Attachments
Activity
- All
- Comments
- Work Log
- History
- Activity
- Transitions
Valgrind did not show something wrong.
Just to make sure – have you noticed that it's, first of all, a loop? The stack trace contains almost 9K frames, most of which are in Item_ref::real_item.
Replacing equal fileds replace field where the Item_direct_view_ref points with pointers on itself. sot *(Item_ref::ref) points back on the Item.
Item_direct_view_ref is best choice to replace bacause it is a constant (8 in the example).
This patch is wrong because changes results:
=== modified file 'sql/item_cmpfunc.h'
— sql/item_cmpfunc.h 2012-11-12 20:14:16 +0000
+++ sql/item_cmpfunc.h 2012-11-28 19:27:20 +0000
@@ -1718,7 +1718,8 @@ class Item_equal: public Item_bool_func
Item_equal(Item *f1, Item *f2, bool with_const_item);
Item_equal(Item_equal *item_equal);
/* Currently the const item is always the first in the list of equal items */
- inline Item* get_const()
{ return with_const ? equal_items.head() : NULL; }
+ inline Item* get_const()
{ return with_const ? equal_items.head()->real_item() : NULL; }
+void add_const(Item *c, Item *f = NULL);
{ equal_items.push_back(f); }
/** Add a non-constant item to the multiple equality */
void add(Item *f)
Let's try to check that items are the same when build multy equality...
The problem was in unwrapping view/subquery-in-the-FROM-clase fields in substitution.
It crashes in calling virtual method of Item_view_direct_ref created for view field. According to the debug log and data in the fields of the object it should be valid.