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Remove redundant code in opt_sum_query()

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unknown 2006-04-06 21:42:03 +04:00
parent a0f7e7558f
commit 3daaa8d5f4
1 changed files with 7 additions and 20 deletions
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27
sql/opt_sum.cc
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@ -123,8 +123,11 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
If the storage manager of 'tl' gives exact row count, compute the total
number of rows. If there are no outer table dependencies, this count
may be used as the real count.
Schema tables are filled after this function is invoked, so we can't
get row count
*/
if (tl->table->file->table_flags() & HA_NOT_EXACT_COUNT)
if ((tl->table->file->table_flags() & HA_NOT_EXACT_COUNT) ||
tl->schema_table)
{
is_exact_count= FALSE;
count= 1; // ensure count != 0
@ -149,31 +152,15 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
switch (item_sum->sum_func()) {
case Item_sum::COUNT_FUNC:
/*
If the expr in count(expr) can never be null we can change this
If the expr in COUNT(expr) can never be null we can change this
to the number of rows in the tables if this number is exact and
there are no outer joins.
*/
if (!conds && !((Item_sum_count*) item)->args[0]->maybe_null &&
!outer_tables && is_exact_count)
{
longlong count= 1;
TABLE_LIST *table;
for (table= tables; table; table= table->next_leaf)
{
if (outer_tables || (table->table->file->table_flags() &
HA_NOT_EXACT_COUNT) || table->schema_table)
{
const_result= 0; // Can't optimize left join
break;
}
tables->table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
count*= table->table->file->records;
}
if (!table)
{
((Item_sum_count*) item)->make_const(count);
recalc_const_item= 1;
}
((Item_sum_count*) item)->make_const(count);
recalc_const_item= 1;
}
else
const_result= 0;