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Merge moonbone.local:/work/tmp_merge-4.1

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into  moonbone.local:/work/tmp_merge-4.1-opt-mysql
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evgen@moonbone.local
2006-08-02 16:10:52 +04:00
parent 5d948f5ec4 351554e121
commit 40a1fbdffb
18 changed files with 326 additions and 15 deletions
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35
sql/sql_select.cc
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@ -547,6 +547,24 @@ JOIN::optimize()
}
zero_result_cause= "Select tables optimized away";
tables_list= 0; // All tables resolved
/*
Extract all table-independent conditions and replace the WHERE
clause with them. All other conditions were computed by opt_sum_query
and the MIN/MAX/COUNT function(s) have been replaced by constants,
so there is no need to compute the whole WHERE clause again.
Notice that make_cond_for_table() will always succeed to remove all
computed conditions, because opt_sum_query() is applicable only to
conjunctions.
*/
if (conds)
{
COND *table_independent_conds=
make_cond_for_table(conds, PSEUDO_TABLE_BITS, 0);
DBUG_EXECUTE("where",
print_where(table_independent_conds,
"where after opt_sum_query()"););
conds= table_independent_conds;
}
}
}
if (!tables_list)
@ -2143,8 +2161,11 @@ merge_key_fields(KEY_FIELD *start,KEY_FIELD *new_fields,KEY_FIELD *end,
/* field = expression OR field IS NULL */
old->level= and_level;
old->optimize= KEY_OPTIMIZE_REF_OR_NULL;
/* Remember the NOT NULL value */
if (old->val->is_null())
/*
Remember the NOT NULL value unless the value does not depend
on other tables.
*/
if (!old->val->used_tables() && old->val->is_null())
old->val= new_fields->val;
/* The referred expression can be NULL: */
old->null_rejecting= 0;
@ -4452,10 +4473,16 @@ return_zero_rows(JOIN *join, select_result *result,TABLE_LIST *tables,
DBUG_RETURN(0);
}
/*
used only in JOIN::clear
*/
static void clear_tables(JOIN *join)
{
for (uint i=0 ; i < join->tables ; i++)
/*
must clear only the non-const tables, as const tables
are not re-calculated.
*/
for (uint i=join->const_tables ; i < join->tables ; i++)
mark_as_null_row(join->table[i]); // All fields are NULL
}