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authorIgor Babaev <igor@askmonty.org>2018-04-24 15:51:49 -0700
committerIgor Babaev <igor@askmonty.org>2018-04-25 09:22:06 -0700
commiteb057dce2027b673b7b140bae42963774027e0a5 (patch)
treeaa2b16fc6680af2df57c5b3f1cd91a69be3f4e98 /sql/item_func.h
parentadaa891ae7113069e402b40637dd9ddbd96d27bc (diff)
downloadmariadb-git-eb057dce2027b673b7b140bae42963774027e0a5.tar.gz
MDEV-15035 Wrong results when calling a stored procedure
multiple times with different arguments. If the ON expression of an outer join is an OR formula with one of the disjunct being a constant formula then the expression cannot be null-rejected if the constant formula is true. Otherwise it can be null-rejected and if so the outer join can be converted into inner join. This optimization was added in the patch for mdev-4817. Yet the code had a defect: if the query was used in a stored procedure with parameters and the constant item contained some of them then the value of this constant item depended on the values of the parameters. With some parameters it may be true, for others not. The validity of conversion to inner join is checked only once and it happens only for the first call of procedure. So if the parameters in the first call allowed the conversion it was done and next calls used the transformed query though there could be calls whose parameters made the conversion invalid. Fixed by cheking whether the constant disjunct in the ON expression originally contained an SP parameter. If so the expression is not considered as null-rejected. For this check a new item's attribute was intruduced: Item::with_param. It is calculated for each item by fix fields() functions. Also moved the call of optimize_constant_subqueries() in JOIN::optimize after the call of simplify_joins(). The reason for this is that after the optimization introduced by the patch for mdev-4817 simplify_joins() can use the results of execution of non-expensive constant subqueries and this is not valid.
Diffstat (limited to 'sql/item_func.h')
-rw-r--r--sql/item_func.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/sql/item_func.h b/sql/item_func.h
index 57818228b98..3a609fc0fe0 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -83,6 +83,7 @@ public:
args= tmp_arg;
args[0]= a;
with_sum_func= a->with_sum_func;
+ with_param= a->with_param;
with_field= a->with_field;
}
Item_func(Item *a,Item *b):
@@ -91,6 +92,7 @@ public:
args= tmp_arg;
args[0]= a; args[1]= b;
with_sum_func= a->with_sum_func || b->with_sum_func;
+ with_param= a->with_param || b->with_param;
with_field= a->with_field || b->with_field;
}
Item_func(Item *a,Item *b,Item *c):
@@ -102,6 +104,7 @@ public:
arg_count= 3;
args[0]= a; args[1]= b; args[2]= c;
with_sum_func= a->with_sum_func || b->with_sum_func || c->with_sum_func;
+ with_param= a->with_param || b->with_param || c->with_param;
with_field= a->with_field || b->with_field || c->with_field;
}
}
@@ -115,6 +118,8 @@ public:
args[0]= a; args[1]= b; args[2]= c; args[3]= d;
with_sum_func= a->with_sum_func || b->with_sum_func ||
c->with_sum_func || d->with_sum_func;
+ with_param= a->with_param || b->with_param ||
+ c->with_param || d->with_param;
with_field= a->with_field || b->with_field ||
c->with_field || d->with_field;
}
@@ -128,6 +133,8 @@ public:
args[0]= a; args[1]= b; args[2]= c; args[3]= d; args[4]= e;
with_sum_func= a->with_sum_func || b->with_sum_func ||
c->with_sum_func || d->with_sum_func || e->with_sum_func ;
+ with_param= a->with_param || b->with_param ||
+ c->with_param || d->with_param || e->with_param;
with_field= a->with_field || b->with_field ||
c->with_field || d->with_field || e->with_field;
}