3437 Jorgen Loland 2011-09-20
Cleanup in the optimizer:
* Rename JT_NEXT to JT_INDEX_SCAN
* Remove JT_MAYBE_REF (unused)
* Document what the join_type names mean
modified:
sql/opt_explain.cc
sql/sql_select.cc
sql/sql_select.h
3436 Jorgen Loland 2011-09-14
Recorded result files after merge mysql-trunk -> opt-backporting.
modified:
mysql-test/r/innodb_icp_all.result
mysql-test/r/innodb_mrr_all.result
mysql-test/r/innodb_mrr_cost_all.result
mysql-test/r/myisam_icp_all.result
mysql-test/r/subquery_sj_none_bka_nobnl.result
=== modified file 'sql/opt_explain.cc'
--- a/sql/opt_explain.cc 2011-08-29 11:57:44 +0000
+++ b/sql/opt_explain.cc 2011-09-20 13:07:55 +0000
@@ -848,7 +848,7 @@ bool Explain_join::explain_key_and_len()
{
if (tab->ref.key_parts)
return explain_key_and_len_index(tab->ref.key, tab->ref.key_length);
- else if (tab->type == JT_NEXT)
+ else if (tab->type == JT_INDEX_SCAN)
return explain_key_and_len_index(tab->index);
else if (tab->select && tab->select->quick)
return explain_key_and_len_quick(tab->select);
@@ -908,7 +908,7 @@ bool Explain_join::explain_rows_and_filt
double examined_rows;
if (tab->select && tab->select->quick)
examined_rows= rows2double(tab->select->quick->records);
- else if (tab->type == JT_NEXT || tab->type == JT_ALL)
+ else if (tab->type == JT_INDEX_SCAN || tab->type == JT_ALL)
{
if (tab->limit)
examined_rows= rows2double(tab->limit);
@@ -993,7 +993,7 @@ bool Explain_join::explain_extra()
else
str_extra.append(STRING_WITH_LEN("; Scanned all databases"));
}
- if (((tab->type == JT_NEXT || tab->type == JT_CONST) &&
+ if (((tab->type == JT_INDEX_SCAN || tab->type == JT_CONST) &&
table->covering_keys.is_set(tab->index)) ||
(quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT &&
!((QUICK_ROR_INTERSECT_SELECT*) select->quick)->need_to_fetch_row) ||
=== modified file 'sql/sql_select.cc'
--- a/sql/sql_select.cc 2011-09-14 11:44:36 +0000
+++ b/sql/sql_select.cc 2011-09-20 13:07:55 +0000
@@ -12426,7 +12426,7 @@ make_join_readinfo(JOIN *join, ulonglong
if (!tab->loosescan_match_tab)
tab->index=find_shortest_key(table, & table->covering_keys);
tab->read_first_record= join_read_first;
- tab->type=JT_NEXT; // Read with index_first / index_next
+ tab->type=JT_INDEX_SCAN; // Read with index_first / index_next
}
}
if (tab->select && tab->select->quick &&
@@ -12434,7 +12434,8 @@ make_join_readinfo(JOIN *join, ulonglong
push_index_cond(tab, tab->select->quick->index, icp_other_tables_ok);
}
trace_refine_table.add_alnum("scan_type",
- tab->type == JT_NEXT ? "index" : "table");
+ tab->type == JT_INDEX_SCAN ?
+ "index" : "table");
break;
case JT_FT:
break;
@@ -12442,7 +12443,6 @@ make_join_readinfo(JOIN *join, ulonglong
DBUG_PRINT("error",("Table type %d found",tab->type)); /* purecov: deadcode */
break; /* purecov: deadcode */
case JT_UNKNOWN:
- case JT_MAYBE_REF:
abort(); /* purecov: deadcode */
}
// Materialize derived tables prior to accessing them.
@@ -21687,7 +21687,7 @@ check_reverse_order:
tab->index= best_key;
tab->read_first_record= order_direction > 0 ?
join_read_first:join_read_last;
- tab->type=JT_NEXT; // Read with index_first(), index_next()
+ tab->type=JT_INDEX_SCAN; // Read with index_first(), index_next()
if (table->covering_keys.is_set(best_key))
table->set_keyread(TRUE);
@@ -21746,7 +21746,7 @@ check_reverse_order:
save_quick= 0; // make_reverse() consumed it
select->set_quick(tmp);
}
- else if (tab->type != JT_NEXT && tab->type != JT_REF_OR_NULL &&
+ else if (tab->type != JT_INDEX_SCAN && tab->type != JT_REF_OR_NULL &&
tab->ref.key >= 0 && tab->ref.key_parts <= used_key_parts)
{
/*
=== modified file 'sql/sql_select.h'
--- a/sql/sql_select.h 2011-08-29 11:57:44 +0000
+++ b/sql/sql_select.h 2011-09-20 13:07:55 +0000
@@ -224,9 +224,68 @@ typedef struct st_table_ref : public Sql
/*
The structs which holds the join connections and join states
*/
-enum join_type { JT_UNKNOWN,JT_SYSTEM,JT_CONST,JT_EQ_REF,JT_REF,JT_MAYBE_REF,
- JT_ALL, JT_RANGE, JT_NEXT, JT_FT, JT_REF_OR_NULL,
- JT_UNIQUE_SUBQUERY, JT_INDEX_SUBQUERY, JT_INDEX_MERGE};
+enum join_type { /*
+ Initial state. Access type has not yet been decided
+ for the table
+ */
+ JT_UNKNOWN,
+ /* Table has exactly one row */
+ JT_SYSTEM,
+ /*
+ Table has at most one matching row. Values read
+ from this row can be treated as constants. Example:
+ "WHERE table.pk = 3"
+ */
+ JT_CONST,
+ /*
+ '=' operator is used on unique index. At most one
+ row is read for each combination of rows from
+ preceding tables
+ */
+ JT_EQ_REF,
+ /*
+ '=' operator is used on non-unique index
+ */
+ JT_REF,
+ /*
+ Full table scan or range scan.
+ If select->quick != NULL, it is range access.
+ Otherwise it is table scan.
+ */
+ JT_ALL,
+ /*
+ Range scan. Note that range scan is not indicated
+ by JT_RANGE but by "JT_ALL + select->quick" except
+ when printing EXPLAIN output. @see calc_join_type()
+ */
+ JT_RANGE,
+ /*
+ Like table scan, but scans index leaves instead of
+ the table
+ */
+ JT_INDEX_SCAN,
+ /* Fulltext index is used */
+ JT_FT,
+ /*
+ Like ref, but with extra search for NULL values.
+ E.g. used for "WHERE col = ... OR col IS NULL"
+ */
+ JT_REF_OR_NULL,
+ /*
+ Like eq_ref for subqueries: Replaces subquery with
+ index lookup in unique index
+ */
+ JT_UNIQUE_SUBQUERY,
+ /*
+ Like unique_subquery but for non-unique index
+ */
+ JT_INDEX_SUBQUERY,
+ /*
+ Do multiple range scans over one table and combine
+ the results into one. The merge can be used to
+ produce unions and intersections
+ */
+ JT_INDEX_MERGE};
class JOIN;
No bundle (reason: useless for push emails).
| Thread |
|---|
| • bzr push into mysql-trunk branch (jorgen.loland:3436 to 3437) | Jorgen Loland | 20 Sep |
