diff options
Diffstat (limited to 'sql/multi_range_read.cc')
| -rw-r--r-- | sql/multi_range_read.cc | 75 |
1 files changed, 36 insertions, 39 deletions
diff --git a/sql/multi_range_read.cc b/sql/multi_range_read.cc index e86bd8470b7..083f18f86c8 100644 --- a/sql/multi_range_read.cc +++ b/sql/multi_range_read.cc @@ -400,17 +400,6 @@ void SimpleBuffer::reset_for_writing() write_pos= read_pos= end; } -void SimpleBuffer::reset_for_reading() -{ -/* -Do we need this at all? - if (direction == 1) - pos= start; - else - pos= end; -//end? -*/ -} uchar *SimpleBuffer::end_of_space() { @@ -478,15 +467,20 @@ int DsMrr_impl::dsmrr_init(handler *h_arg, RANGE_SEQ_IF *seq_funcs, use_key_pointers= test(mode & HA_MRR_MATERIALIZED_KEYS); } - do_rowid_fetch= FALSE; - doing_cpk_scan= check_cpk_scan(thd, h->inited == handler::INDEX? + do_rndpos_scan= FALSE; + bool doing_cpk_scan= check_cpk_scan(thd, h->inited == handler::INDEX? h->active_index: h2->active_index, mode); if (!doing_cpk_scan /* && !index_only_read */) { /* Will use rowid buffer to store/sort rowids, etc */ - do_rowid_fetch= TRUE; + do_rndpos_scan= TRUE; } - DBUG_ASSERT(do_sort_keys || do_rowid_fetch); + + /* + We should either sort keys, or do ordered rnd_pos scan, or both. If we + decide to do neither, we should have used default MRR implementation. + */ + DBUG_ASSERT(do_sort_keys || do_rndpos_scan); if (is_mrr_assoc) @@ -509,11 +503,11 @@ int DsMrr_impl::dsmrr_init(handler *h_arg, RANGE_SEQ_IF *seq_funcs, keyno= (h->inited == handler::INDEX)? h->active_index : h2->active_index; dsmrr_fill_key_buffer(); - if (dsmrr_eof && !do_rowid_fetch) + if (dsmrr_eof && !do_rndpos_scan) buf->end_of_used_area= key_buffer.end_of_space(); } - if (!do_rowid_fetch) + if (!do_rndpos_scan) { /* We have the keys and won't need to fetch rowids, as key lookup will be @@ -524,11 +518,6 @@ int DsMrr_impl::dsmrr_init(handler *h_arg, RANGE_SEQ_IF *seq_funcs, rowid_buff_elem_size= h->ref_length + (is_mrr_assoc? sizeof(char*) : 0); /* - psergey2: this is only needed when - - doing a rowid-to-row scan - - the buffer wasn't exhausted on the first pass. - */ - /* There can be two cases: - This is the first call since index_init(), h2==NULL Need to setup h2 then. @@ -821,7 +810,7 @@ void DsMrr_impl::setup_buffer_sizes(key_range *sample_key) index_ranges_unique= test(key_info->flags & HA_NOSAME && key_info->key_parts == my_count_bits(sample_key->keypart_map)); - if (!do_rowid_fetch) + if (!do_rndpos_scan) { /* Give all space to key buffer. */ key_buffer.set_buffer_space(full_buf, full_buf_end, SimpleBuffer::FORWARD); @@ -908,7 +897,7 @@ void DsMrr_impl::dsmrr_fill_key_buffer() uchar *key_ptr; if (know_key_tuple_params) { - if (do_rowid_fetch && rowid_buffer.is_empty()) + if (do_rndpos_scan && rowid_buffer.is_empty()) { /* We're using two buffers and both of them are empty now. Restore the @@ -964,6 +953,18 @@ void DsMrr_impl::dsmrr_fill_key_buffer() /* + Take unused space from key buffer and give it to rowid buffer. +*/ + +void DsMrr_impl::reallocate_buffer_space() +{ + uchar *unused_start, *unused_end; + key_buffer.remove_unused_space(&unused_start, &unused_end); + rowid_buffer.grow(unused_start, unused_end); +} + + +/* DS-MRR/CPK: multi_range_read_next() function DESCRIPTION @@ -993,7 +994,7 @@ int DsMrr_impl::dsmrr_next_from_index(char **range_info_arg) { int res; uchar *key_in_buf; - handler *file= do_rowid_fetch? h2: h; + handler *file= do_rndpos_scan? h2: h; bool res2; while (in_identical_keys_range) @@ -1068,7 +1069,7 @@ check_record: When rowid fetching is used, it controls all buffer refills. When we're on our own, try refilling our buffer. */ - if (!do_rowid_fetch) + if (!do_rndpos_scan) dsmrr_fill_key_buffer(); if (key_buffer.is_empty()) @@ -1078,17 +1079,13 @@ check_record: } } - if (do_rowid_fetch) - { - /* - At this point we're not using anything what we've read from key - buffer. Cut off unused key buffer space and give it to the rowid - buffer. - */ - uchar *unused_start, *unused_end; - key_buffer.remove_unused_space(&unused_start, &unused_end); - rowid_buffer.grow(unused_start, unused_end); - } + /* + At this point we're not using anything what we've read from key + buffer. Cut off unused key buffer space and give it to the rowid + buffer. + */ + if (do_rndpos_scan) + reallocate_buffer_space(); /* Get the next range to scan */ key_buffer.read(); // reads to (cur_index_tuple, cur_range_info) @@ -1147,7 +1144,7 @@ int DsMrr_impl::dsmrr_next(char **range_info) if (use_default_impl) return h->handler::multi_range_read_next(range_info); - if (!do_rowid_fetch) + if (!do_rndpos_scan) return dsmrr_next_from_index(range_info); while (last_identical_rowid) @@ -1421,7 +1418,7 @@ bool DsMrr_impl::choose_mrr_impl(uint keyno, ha_rows rows, uint *flags, bool res; THD *thd= current_thd; - doing_cpk_scan= check_cpk_scan(thd, keyno, *flags); + bool doing_cpk_scan= check_cpk_scan(thd, keyno, *flags); bool using_cpk= test(keyno == table->s->primary_key && h->primary_key_is_clustered()); if (thd->variables.optimizer_use_mrr == 2 || *flags & HA_MRR_INDEX_ONLY || |