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BUG#26624: high mem usage (crash) in range optimizer

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- Post-review fixes
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unknown
2007-03-29 10:27:58 +04:00
parent edd5a85948
commit 9b358f811b
1 changed files with 15 additions and 14 deletions
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29
sql/opt_range.cc
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@@ -175,7 +175,7 @@ static char is_null_string[2]= {1,0};
Example:
By induction: Let's take any interval on some keypart in the middle:
kp15=1
kp15=c0
Then let's AND it with this interval 'structure' from preceding and
following keyparts:
@@ -184,18 +184,18 @@ static char is_null_string[2]= {1,0};
We will obtain this SEL_ARG graph:
kp14 $ kp15 $ kp16
$ $
+---------+ $ +--------+ $ +---------+
| kp14=c1 |--$-->| kp15=1 |--$-->| kp16=c3 |
+---------+ $ +--------+ $ +---------+
| $ $
+---------+ $ +--------+ $
| kp14=c2 |--$-->| kp15=1 | $
+---------+ $ +--------+ $
$ $
kp14 $ kp15 $ kp16
$ $
+---------+ $ +---------+ $ +---------+
| kp14=c1 |--$-->| kp15=c0 |--$-->| kp16=c3 |
+---------+ $ +---------+ $ +---------+
| $ $
+---------+ $ +---------+ $
| kp14=c2 |--$-->| kp15=c0 | $
+---------+ $ +---------+ $
$ $
Note that we had to duplicate "kp15=1" and there was no way to avoid
Note that we had to duplicate "kp15=c0" and there was no way to avoid
that.
The induction step: AND the obtained expression with another "wrapping"
expression like (*).
@@ -477,7 +477,7 @@ typedef struct st_qsel_param {
max_key[MAX_KEY_LENGTH+MAX_FIELD_WIDTH];
bool quick; // Don't calulate possible keys
COND *cond;
/* Numbr of SEL_ARG objects allocated by SEL_ARG::clone_tree operations */
/* Number of SEL_ARG objects allocated by SEL_ARG::clone_tree operations */
uint alloced_sel_args;
} PARAM;
@@ -681,7 +681,8 @@ SEL_ARG *SEL_ARG::clone(PARAM *param, SEL_ARG *new_parent, SEL_ARG **next_arg)
tmp->parent=new_parent;
tmp->next_key_part=next_key_part;
if (left != &null_element)
tmp->left=left->clone(param, tmp, next_arg);
if (!(tmp->left=left->clone(param, tmp, next_arg)))
return 0; // OOM
tmp->prev= *next_arg; // Link into next/prev chain
(*next_arg)->next=tmp;