diff options
Diffstat (limited to 'sql/uniques.cc')
| -rw-r--r-- | sql/uniques.cc | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/sql/uniques.cc b/sql/uniques.cc index fafb44b56a0..1b8e91f2566 100644 --- a/sql/uniques.cc +++ b/sql/uniques.cc @@ -318,6 +318,9 @@ double Unique::get_use_cost(uint *buffer, size_t nkeys, uint key_size, max_elements_in_tree= ((size_t) max_in_memory_size / ALIGN_SIZE(sizeof(TREE_ELEMENT)+key_size)); + if (max_elements_in_tree == 0) + max_elements_in_tree= 1; + n_full_trees= nkeys / max_elements_in_tree; last_tree_elems= nkeys % max_elements_in_tree; @@ -786,7 +789,12 @@ bool Unique::get(TABLE *table) /* Not enough memory; Save the result to file && free memory used by tree */ if (flush()) DBUG_RETURN(1); - size_t buff_sz= (max_in_memory_size / full_size + 1) * full_size; + /* + merge_buffer must fit at least MERGEBUFF2 + 1 keys, because + merge_index() can merge that many BUFFPEKs at once. The extra space for + one key for Sort_param::unique_buff + */ + size_t buff_sz= MY_MAX(MERGEBUFF2+1, max_in_memory_size/full_size+1) * full_size; if (!(sort_buffer= (uchar*) my_malloc(buff_sz, MYF(MY_THREAD_SPECIFIC|MY_WME)))) DBUG_RETURN(1); |