diff options
Diffstat (limited to 'sql/sql_join_cache.cc')
| -rw-r--r-- | sql/sql_join_cache.cc | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/sql/sql_join_cache.cc b/sql/sql_join_cache.cc index 4148842a826..1f375bf1a03 100644 --- a/sql/sql_join_cache.cc +++ b/sql/sql_join_cache.cc @@ -681,7 +681,23 @@ void JOIN_CACHE::set_constants() uint len= length + fields*sizeof(uint)+blobs*sizeof(uchar *) + (prev_cache ? prev_cache->get_size_of_rec_offset() : 0) + sizeof(ulong); - buff_size= max(join->thd->variables.join_buff_size, 2*len); + /* + The values of size_of_rec_ofs, size_of_rec_len, size_of_fld_ofs, + base_prefix_length, pack_length, pack_length_with_blob_ptrs + will be recalculated later in this function when we get the estimate + for the actual value of the join buffer size. + */ + size_of_rec_ofs= size_of_rec_len= size_of_fld_ofs= 4; + base_prefix_length= (with_length ? size_of_rec_len : 0) + + (prev_cache ? prev_cache->get_size_of_rec_offset() : 0); + pack_length= (with_length ? size_of_rec_len : 0) + + (prev_cache ? prev_cache->get_size_of_rec_offset() : 0) + + length + fields*sizeof(uint); + pack_length_with_blob_ptrs= pack_length + blobs*sizeof(uchar *); + min_buff_size= 0; + min_records= 1; + buff_size= max(join->thd->variables.join_buff_size, + get_min_join_buffer_size()); size_of_rec_ofs= offset_size(buff_size); size_of_rec_len= blobs ? size_of_rec_ofs : offset_size(len); size_of_fld_ofs= size_of_rec_len; @@ -754,19 +770,24 @@ ulong JOIN_CACHE::get_min_join_buffer_size() if (!min_buff_size) { size_t len= 0; + size_t len_last= 0; for (JOIN_TAB *tab= start_tab; tab != join_tab; tab= next_linear_tab(join, tab, WITHOUT_BUSH_ROOTS)) { len+= tab->get_max_used_fieldlength(); + len_last=+ tab->get_used_fieldlength(); } - len+= get_record_max_affix_length() + get_max_key_addon_space_per_record(); - size_t min_sz= len*min_records; + size_t len_addon= get_record_max_affix_length() + + get_max_key_addon_space_per_record(); + len+= len_addon; + len_last+= len_addon; + size_t min_sz= len*(min_records-1) + len_last; + min_sz+= pack_length_with_blob_ptrs; size_t add_sz= 0; for (uint i=0; i < min_records; i++) add_sz+= join_tab_scan->aux_buffer_incr(i+1); avg_aux_buffer_incr= add_sz/min_records; min_sz+= add_sz; - min_sz+= pack_length_with_blob_ptrs; set_if_bigger(min_sz, 1); min_buff_size= min_sz; } |