#At file:///home/psergey/dev/mysql-6.0-subq-r16/
2686 Sergey Petrunia 2008-07-28
Remove deadcode - old version of setup_semijoin_dups_elimination()
modified:
sql/sql_select.cc
per-file messages:
sql/sql_select.cc
Remove deadcode - old version of setup_semijoin_dups_elimination()
=== modified file 'sql/sql_select.cc'
--- a/sql/sql_select.cc 2008-07-28 15:44:17 +0000
+++ b/sql/sql_select.cc 2008-07-28 15:48:11 +0000
@@ -1162,266 +1162,6 @@ TABLE *create_duplicate_weedout_tmp_tabl
FALSE OK
TRUE Out of memory error
*/
-#if 0
-static
-int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, uint no_jbuf_after)
-{
- table_map cur_map= join->const_table_map | PSEUDO_TABLE_BITS;
- enum sj_strategy_enum {
- SJ_STRATEGY_INVALID,
- SJ_STRATEGY_INSIDEOUT,
- SJ_STRATEGY_DUPS_WEEDOUT,
- SJ_STRATEGY_DUPS_WEEDOUT_JBUF
- };
- struct {
- /*
- 0 - invalid (EOF marker),
- 1 - LooseScan,
- 2 - Temptable (maybe confluent),
- 3 - Temptable with join buffering
- */
- enum sj_strategy_enum strategy;
- uint start_idx; /* Left range bound */
- uint end_idx; /* Right range bound */
- /*
- For Temptable strategy: Bitmap of all outer and correlated tables from
- all involved join nests.
- */
- table_map outer_tables;
- } dups_ranges [MAX_TABLES];
-
- TABLE_LIST *emb_insideout_nest= NULL;
- table_map emb_sj_map= 0; /* A bitmap of sj-nests (that is, their sj-inner
- tables) whose ranges we're in */
- table_map emb_outer_tables= 0; /* sj-outer tables for those sj-nests */
- table_map range_start_map; /* table_map at current range start */
- bool dealing_with_jbuf= FALSE; /* TRUE <=> table within cur range uses join buf */
- int cur_range= 0;
- uint i;
-
- DBUG_ENTER("setup_semijoin_dups_elimination");
- LINT_INIT(range_start_map); // protected by emb_sj_map
- /*
- First pass: locate the duplicate-generating ranges and pick the strategies.
- */
- for (i= join->const_tables ; i < join->tables ; i++)
- {
- JOIN_TAB *tab=join->join_tab+i;
- TABLE *table=tab->table;
- cur_map |= table->map;
-
- if (join->best_positions[i].use_sj_mat)
- continue;
-
- if (tab->emb_sj_nest) // Encountered an sj-inner table
- {
- if (!emb_sj_map)
- {
- dups_ranges[cur_range].start_idx= i;
- range_start_map= cur_map & ~table->map;
- /*
- Remember if this is a possible start of range that is covered by
- the LooseScan strategy (the reason that it is not covered could
- be that it overlaps with anther semi-join's range. we don't
- support LooseScan for joined ranges)
- */
- if (join->best_positions[i].loosescan_key != MAX_KEY)
- emb_insideout_nest= tab->emb_sj_nest;
- }
-
- emb_sj_map |= tab->emb_sj_nest->sj_inner_tables;
- emb_outer_tables |= tab->emb_sj_nest->nested_join->sj_depends_on;
-
- if (tab->emb_sj_nest != emb_insideout_nest)
- {
- /*
- Two different semi-joins interleave. This cannot be handled by
- LooseScan strategy.
- */
- emb_insideout_nest= NULL;
- }
- }
-
- if (emb_sj_map) /* We're in duplicate-generating range */
- {
- if (i != join->const_tables && !(options & SELECT_NO_JOIN_CACHE) &&
- tab->type == JT_ALL && tab->use_quick != 2 && !tab->first_inner &&
- i <= no_jbuf_after && !dealing_with_jbuf)
- {
- /*
- This table uses join buffering, which makes use of FirstMatch or
- LooseScan strategies impossible for the current and (we assume)
- preceding duplicate-producing ranges.
- That is, for the join order:
-
- x x [ x x] x [x x x] x [x x X* x] x
- | | | | | \
- +-----+ +-----+ | join buffering use
- r1 r2 we're here
-
- we'll have to remove r1 and r2 and use duplicate-elimination
- strategy that spans all the tables, starting from the very 1st
- one.
- */
- dealing_with_jbuf= TRUE;
- emb_insideout_nest= FALSE;
-
- /*
- Absorb all preceding duplicate-eliminating ranges. Their strategies
- do not matter:
- */
- for (int prev_range= 0; prev_range < cur_range; prev_range++)
- {
- dups_ranges[cur_range].outer_tables |=
- dups_ranges[prev_range].outer_tables;
- }
- dups_ranges[0].start_idx= 0; /* Will need to start from the 1st table */
- dups_ranges[0].outer_tables= dups_ranges[cur_range].outer_tables;
- cur_range= 0;
- }
-
- /*
- Check if we are at the end of duplicate-producing range. We are if
-
- 1. It's an LooseScan range (which presumes all correlated tables are
- in the prefix), and all inner tables are in the join order prefix,
- or
- 2. It's a DuplicateElimination range (possibly covering several
- SJ-nests), and all inner, outer, and correlated tables of all
- sj-nests are in the join order prefix.
- */
- bool end_of_range= FALSE;
- if (emb_insideout_nest &&
- bitmap_covers(cur_map, emb_insideout_nest->sj_inner_tables))
- {
- /* Save that this range is handled with LooseScan: */
- dups_ranges[cur_range].strategy= SJ_STRATEGY_INSIDEOUT;
- end_of_range= TRUE;
- }
- else if (bitmap_covers(cur_map, emb_outer_tables | emb_sj_map))
- {
- /*
- This is a complete range to be handled with either DuplicateWeedout
- or FirstMatch
- */
- dups_ranges[cur_range].strategy=
- dealing_with_jbuf? SJ_STRATEGY_DUPS_WEEDOUT_JBUF:
- SJ_STRATEGY_DUPS_WEEDOUT;
- /*
- This will hold tables from within the range that need to be put
- into the join buffer before we can use the FirstMatch on its tail.
- */
- dups_ranges[cur_range].outer_tables= emb_outer_tables &
- ~range_start_map;
- end_of_range= TRUE;
- }
-
- if (end_of_range)
- {
- dups_ranges[cur_range].end_idx= i+1;
- emb_sj_map= emb_outer_tables= 0;
- emb_insideout_nest= NULL;
- dealing_with_jbuf= FALSE;
- dups_ranges[++cur_range].strategy= SJ_STRATEGY_INVALID;
- }
- else
- {
- /* We don't support interleaving for LooseScan*/
- if (!tab->emb_sj_nest)
- emb_insideout_nest= NULL;
- }
- }
- }
-
- THD *thd= join->thd;
- /*
- The second pass: setup the chosen strategies
- */
- for (int j= 0; j < cur_range; j++)
- {
- JOIN_TAB *tab=join->join_tab + dups_ranges[j].start_idx;
- JOIN_TAB *jump_to;
- if (dups_ranges[j].strategy == SJ_STRATEGY_INSIDEOUT)
- {
- ...
- }
- else // DuplicateWeedout or FirstMatch
- {
- SJ_TMP_TABLE::TAB sjtabs[MAX_TABLES];
- table_map cur_map= join->const_table_map | PSEUDO_TABLE_BITS;
- uint jt_rowid_offset= 0; // # tuple bytes are already occupied (w/o NULL bytes)
- uint jt_null_bits= 0; // # null bits in tuple bytes
- SJ_TMP_TABLE::TAB *last_tab= sjtabs;
- uint rowid_keep_flags= JOIN_TAB::CALL_POSITION | JOIN_TAB::KEEP_ROWID;
- JOIN_TAB *last_outer_tab= tab - 1;
- /*
- Walk through the range and remember
- - tables that need their rowids to be put into temptable
- - the last outer table
- */
- for (; tab < join->join_tab + dups_ranges[j].end_idx; tab++)
- {
- if (sj_table_is_included(join, tab))
- {
- last_tab->join_tab= tab;
- last_tab->rowid_offset= jt_rowid_offset;
- jt_rowid_offset += tab->table->file->ref_length;
- if (tab->table->maybe_null)
- {
- last_tab->null_byte= jt_null_bits / 8;
- last_tab->null_bit= jt_null_bits++;
- }
- last_tab++;
- tab->table->prepare_for_position();
- tab->rowid_keep_flags= rowid_keep_flags;
- }
- cur_map |= tab->table->map;
- if (!tab->emb_sj_nest && bitmap_covers(cur_map,
- dups_ranges[j].outer_tables))
- last_outer_tab= tab;
- }
-
- if (jt_rowid_offset) /* Temptable has at least one rowid */
- {
- SJ_TMP_TABLE *sjtbl;
- uint tabs_size= (last_tab - sjtabs) * sizeof(SJ_TMP_TABLE::TAB);
- if (!(sjtbl= (SJ_TMP_TABLE*)thd->alloc(sizeof(SJ_TMP_TABLE))) ||
- !(sjtbl->tabs= (SJ_TMP_TABLE::TAB*) thd->alloc(tabs_size)))
- DBUG_RETURN(TRUE);
- memcpy(sjtbl->tabs, sjtabs, tabs_size);
- sjtbl->tabs_end= sjtbl->tabs + (last_tab - sjtabs);
- sjtbl->rowid_len= jt_rowid_offset;
- sjtbl->null_bits= jt_null_bits;
- sjtbl->null_bytes= (jt_null_bits + 7)/8;
-
-
- sjtbl->tmp_table=
- create_duplicate_weedout_tmp_table(thd,
- sjtbl->rowid_len +
- sjtbl->null_bytes,
- sjtbl);
-
- join->sj_tmp_tables.push_back(sjtbl->tmp_table);
- join->join_tab[dups_ranges[j].start_idx].flush_weedout_table= sjtbl;
- join->join_tab[dups_ranges[j].end_idx - 1].check_weed_out_table= sjtbl;
- }
- tab= last_outer_tab + 1;
- jump_to= last_outer_tab;
- }
-
- /* Create the FirstMatch tail */
- for (; tab < join->join_tab + dups_ranges[j].end_idx; tab++)
- {
- if (!tab->emb_sj_nest)
- jump_to= tab;
- }
- if (tab - 1 != jump_to)
- tab[-1].do_firstmatch= jump_to;
- }
- DBUG_RETURN(FALSE);
-}
-#endif
-
int setup_semijoin_dups_elimination2(JOIN *join, ulonglong options, uint no_jbuf_after)
{
| Thread |
|---|
| • bzr commit into mysql-6.0-opt-subqueries branch (sergefp:2686) | Sergey Petrunia | 28 Jul |
