diff options
Diffstat (limited to 'sql/uniques.cc')
| -rw-r--r-- | sql/uniques.cc | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/sql/uniques.cc b/sql/uniques.cc index fc6437a2f64..e7dc40a5a5f 100644 --- a/sql/uniques.cc +++ b/sql/uniques.cc @@ -101,6 +101,9 @@ Unique::Unique(qsort_cmp2 comp_func, void * comp_func_fixed_arg, */ max_elements= (ulong) (max_in_memory_size / ALIGN_SIZE(sizeof(TREE_ELEMENT)+size)); + if (!max_elements) + max_elements= 1; + (void) open_cached_file(&file, mysql_tmpdir,TEMP_PREFIX, DISK_BUFFER_SIZE, MYF(MY_WME)); } @@ -646,11 +649,12 @@ bool Unique::walk(TABLE *table, tree_walk_action action, void *walk_action_arg) if (flush_io_cache(&file) || reinit_io_cache(&file, READ_CACHE, 0L, 0, 0)) return 1; /* - merge_buffer must fit at least MERGEBUFF2 keys, because - merge_index() can merge that many BUFFPEKs at once. + 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 + is needed when a piece of merge buffer is re-read, see merge_walk() */ - size_t buff_sz= MY_MAX(MERGEBUFF2, max_in_memory_size/full_size+1) * full_size; - if (!(merge_buffer = (uchar *)my_malloc(buff_sz, MYF(MY_THREAD_SPECIFIC|MY_WME)))) + size_t buff_sz= MY_MAX(MERGEBUFF2+1, max_in_memory_size/full_size+1) * full_size; + if (!(merge_buffer = (uchar *)my_malloc(buff_sz, MYF(MY_WME)))) return 1; if (buff_sz < full_size * (file_ptrs.elements + 1UL)) res= merge(table, merge_buffer, buff_sz >= full_size * MERGEBUFF2) ; @@ -708,8 +712,8 @@ bool Unique::merge(TABLE *table, uchar *buff, bool without_last_merge) full_size; sort_param.min_dupl_count= min_dupl_count; sort_param.res_length= 0; - sort_param.max_keys_per_buffer= - (uint) (max_in_memory_size / sort_param.sort_length); + sort_param.max_keys_per_buffer= + (uint) MY_MAX((max_in_memory_size / sort_param.sort_length), MERGEBUFF2); sort_param.not_killable= 1; sort_param.unique_buff= buff +(sort_param.max_keys_per_buffer * |