Hi Sanja, Two questions: 1. Why does the patch define Item_ptr type twice? 2. (The big one) In class Item_in_subselect, I see your comment made in 2015: ... public: Item *left_expr; /* Important for PS/SP: left_expr_orig is the item that left_expr originally pointed at. That item is allocated on the statement arena, while left_expr could later be changed to something on the execution arena. */ Item *left_expr_orig; Considering this comment, is it really safe to keep pointers to left_expr? Should left_expr_orig be used instead? On Sat, Feb 18, 2017 at 05:47:32PM +0100, Oleksandr Byelkin wrote:

revision-id: e0a1e632e4e6084cd989f217943618f4e9ac9179 (mariadb-5.5.54-25-ge0a1e63) parent(s): 29d78dbb44ee9890b6bc28873344f20fc9157928 committer: Oleksandr Byelkin timestamp: 2017-02-18 17:47:31 +0100 message:

MDEV-9619: Assertion `null_ref_table' failed in virtual table_map Item_direct_view_ref::used_tables() const on 2nd execution of PS

Refer left expression indirectly in case it changes from execution to execution.

--- mysql-test/r/ps.result | 24 ++++++++++++++++++++++++ mysql-test/t/ps.test | 22 ++++++++++++++++++++++ sql/item.h | 2 ++ sql/opt_subselect.cc | 10 +++++----- sql/table.h | 3 ++- 5 files changed, 55 insertions(+), 6 deletions(-)

diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result index f954583..7233fe8 100644 --- a/mysql-test/r/ps.result +++ b/mysql-test/r/ps.result @@ -4173,4 +4173,28 @@ Warnings: Note 1003 select `test`.`t1`.`id` AS `id`,`test`.`t1`.`c` AS `c` from `test`.`t1` where 0 deallocate prepare stmt2; drop table t1; +# +# MDEV-9619: Assertion `null_ref_table' failed in virtual +# table_map Item_direct_view_ref::used_tables() const on 2nd +# execution of PS +# +CREATE TABLE t1 (f1 VARCHAR(10)) ENGINE=MyISAM; +CREATE ALGORITHM=MERGE VIEW v1 AS SELECT * FROM t1; +INSERT INTO t1 VALUES ('a'),('b'); +CREATE TABLE t2 (f2 VARCHAR(10)) ENGINE=MyISAM; +INSERT INTO t2 VALUES ('c'),('d'); +PREPARE stmt FROM "SELECT * FROM v1 WHERE f1 = SOME ( SELECT f2 FROM t2 )"; +EXECUTE stmt; +f1 +EXECUTE stmt; +f1 +insert into t1 values ('c'); +EXECUTE stmt; +f1 +c +EXECUTE stmt; +f1 +c +drop view v1; +drop table t1,t2; # End of 5.5 tests diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test index cfd810f..627a9bf 100644 --- a/mysql-test/t/ps.test +++ b/mysql-test/t/ps.test @@ -3714,4 +3714,26 @@ deallocate prepare stmt2;

drop table t1;

+--echo # +--echo # MDEV-9619: Assertion `null_ref_table' failed in virtual +--echo # table_map Item_direct_view_ref::used_tables() const on 2nd +--echo # execution of PS +--echo # + +CREATE TABLE t1 (f1 VARCHAR(10)) ENGINE=MyISAM; +CREATE ALGORITHM=MERGE VIEW v1 AS SELECT * FROM t1; +INSERT INTO t1 VALUES ('a'),('b'); + +CREATE TABLE t2 (f2 VARCHAR(10)) ENGINE=MyISAM; +INSERT INTO t2 VALUES ('c'),('d'); + +PREPARE stmt FROM "SELECT * FROM v1 WHERE f1 = SOME ( SELECT f2 FROM t2 )"; +EXECUTE stmt; +EXECUTE stmt; +insert into t1 values ('c'); +EXECUTE stmt; +EXECUTE stmt; + +drop view v1; +drop table t1,t2; --echo # End of 5.5 tests diff --git a/sql/item.h b/sql/item.h index 89155ac..dff7bc4 100644 --- a/sql/item.h +++ b/sql/item.h @@ -1543,6 +1543,8 @@ class Item { virtual void mark_as_condition_AND_part(TABLE_LIST *embedding) {}; };

+typedef Item (*Item_ptr); +

/** Compare two Items for List<Item>::add_unique() diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index 5137d8a..7f26d01 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -1602,7 +1602,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)

if (subq_pred->left_expr->cols() == 1) { - nested_join->sj_outer_expr_list.push_back(subq_pred->left_expr); + nested_join->sj_outer_expr_list.push_back(&subq_pred->left_expr); /* Create Item_func_eq. Note that 1. this is done on the statement, not execution, arena @@ -1624,7 +1624,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred) for (uint i= 0; i < subq_pred->left_expr->cols(); i++) { nested_join->sj_outer_expr_list.push_back(subq_pred->left_expr-> - element_index(i)); + addr(i)); Item_func_eq *item_eq= new Item_func_eq(subq_pred->left_expr->element_index(i), subq_lex->ref_pointer_array[i]); @@ -3181,8 +3181,8 @@ void restore_prev_sj_state(const table_map remaining_tables, ulonglong get_bound_sj_equalities(TABLE_LIST *sj_nest, table_map remaining_tables) { - List_iterator<Item> li(sj_nest->nested_join->sj_outer_expr_list); - Item *item; + List_iterator<Item_ptr> li(sj_nest->nested_join->sj_outer_expr_list); + Item **item; uint i= 0; ulonglong res= 0; while ((item= li++)) @@ -3193,7 +3193,7 @@ ulonglong get_bound_sj_equalities(TABLE_LIST *sj_nest, class and see if there is an element that is bound? (this is an optional feature) */ - if (!(item->used_tables() & remaining_tables)) + if (!(item[0]->used_tables() & remaining_tables)) { res |= 1ULL << i; } diff --git a/sql/table.h b/sql/table.h index dde01a8..c981243 100644 --- a/sql/table.h +++ b/sql/table.h @@ -33,6 +33,7 @@ /* Structs that defines the TABLE */

class Item; /* Needed by ORDER */ +typedef Item (*Item_ptr); class Item_subselect; class Item_field; class GRANT_TABLE; @@ -2348,7 +2349,7 @@ typedef struct st_nested_join table_map sj_depends_on; /* Outer non-trivially correlated tables */ table_map sj_corr_tables; - List<Item> sj_outer_expr_list; + List<Item_ptr> sj_outer_expr_list; /** True if this join nest node is completely covered by the query execution plan. This means two things. _______________________________________________ commits mailing list commits@mariadb.org https://lists.askmonty.org/cgi-bin/mailman/listinfo/commits

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