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Limit calculated rows to the number of rows in the table

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The result file changes are mainly that number of rows is one smaller
for some queries with DISTINCT or GROUP BY
This commit is contained in:
Monty
2021-10-06 02:39:59 +03:00
committed by Sergei Petrunia
parent c443dbff0e
commit 87d4d7232c
12 changed files with 43 additions and 37 deletions
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14
sql/opt_range.cc
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@@ -3235,7 +3235,7 @@ double records_in_column_ranges(PARAM *param, uint idx,
SEL_ARG_RANGE_SEQ seq;
KEY_MULTI_RANGE range;
range_seq_t seq_it;
double rows;
double rows, table_records;
Field *field;
uint flags= 0;
double total_rows= 0;
@@ -3290,13 +3290,17 @@ double records_in_column_ranges(PARAM *param, uint idx,
total_rows= DBL_MAX;
break;
}
total_rows += rows;
total_rows+= rows;
}
if (total_rows == 0)
total_rows= MY_MIN(1, rows2double(param->table->stat_records()));
return total_rows;
}
table_records= rows2double(param->table->stat_records());
if (total_rows > table_records)
DBUG_PRINT("error", ("table_records: %g < total_records: %g",
table_records, total_rows));
return MY_MIN(total_rows, table_records);
}
/*
@@ -14813,6 +14817,8 @@ void cost_group_min_max(TABLE* table, KEY *index_info, uint used_key_parts,
num_groups= (ha_rows) rint(num_groups * quick_prefix_selectivity);
set_if_bigger(num_groups, 1);
}
/* Ensure we don't have more groups than rows in table */
set_if_smaller(num_groups, table_records);
if (used_key_parts > group_key_parts)
{ /*