diff options
Diffstat (limited to 'sql/opt_subselect.cc')
| -rw-r--r-- | sql/opt_subselect.cc | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index a7e4f982aa2..f2fcca75a8a 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -664,6 +664,17 @@ int check_and_do_in_subquery_rewrites(JOIN *join) DBUG_RETURN(-1); } } + /* Check if any table is not supporting comparable rowids */ + { + List_iterator_fast<TABLE_LIST> li(select_lex->outer_select()->leaf_tables); + TABLE_LIST *tbl; + while ((tbl = li++)) + { + TABLE *table= tbl->table; + if (table && table->file->ha_table_flags() & HA_NON_COMPARABLE_ROWID) + join->not_usable_rowid_map|= table->map; + } + } DBUG_PRINT("info", ("Checking if subq can be converted to semi-join")); /* @@ -683,8 +694,11 @@ int check_and_do_in_subquery_rewrites(JOIN *join) 9. Parent select is not a table-less select 10. Neither parent nor child select have STRAIGHT_JOIN option. 11. It is first optimisation (the subquery could be moved from ON - clause during first optimisation and then be considered for SJ - on the second when it is too late) + clause during first optimisation and then be considered for SJ + on the second when it is too late) + 12. All tables supports comparable rowids. + This is needed for DuplicateWeedout strategy to work (which + is the catch-all semi-join strategy so it must be applicable). */ if (optimizer_flag(thd, OPTIMIZER_SWITCH_SEMIJOIN) && in_subs && // 1 @@ -699,7 +713,8 @@ int check_and_do_in_subquery_rewrites(JOIN *join) !((join->select_options | // 10 select_lex->outer_select()->join->select_options) // 10 & SELECT_STRAIGHT_JOIN) && // 10 - select_lex->first_cond_optimization) // 11 + select_lex->first_cond_optimization && // 11 + join->not_usable_rowid_map == 0) // 12 { DBUG_PRINT("info", ("Subquery is semi-join conversion candidate")); @@ -3557,6 +3572,9 @@ bool Duplicate_weedout_picker::check_qep(JOIN *join, } else { + /* Ensure that table supports comparable rowids */ + DBUG_ASSERT(!(p->table->table->file->ha_table_flags() & HA_NON_COMPARABLE_ROWID)); + sj_outer_fanout= COST_MULT(sj_outer_fanout, p->records_read); temptable_rec_size += p->table->table->file->ref_length; } |