diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/ha_partition.cc | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc index 5b25bd26298..1debc02d7f2 100644 --- a/sql/ha_partition.cc +++ b/sql/ha_partition.cc @@ -6322,7 +6322,17 @@ ha_rows ha_partition::min_rows_for_estimate() DBUG_ENTER("ha_partition::min_rows_for_estimate"); tot_used_partitions= bitmap_bits_set(&m_part_info->used_partitions); - DBUG_ASSERT(tot_used_partitions); + + /* + All partitions might have been left as unused during partition pruning + due to, for example, an impossible WHERE condition. Nonetheless, the + optimizer might still attempt to perform (e.g. range) analysis where an + estimate of the the number of rows is calculated using records_in_range. + Hence, to handle this and other possible cases, use zero as the minimum + number of rows to base the estimate on if no partition is being used. + */ + if (!tot_used_partitions) + DBUG_RETURN(0); /* Allow O(log2(tot_partitions)) increase in number of used partitions. |