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Allow optimzation of multi-table-update also for InnoDB tables

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MEMORY is alias for HEAP for CREATE TABLE ... TYPE=HEAP
Fixed bug in multi-table-update where a row could be updated several times


mysql-test/r/heap.result:
  Test of CREATE TABLE ... type=MEMORY
mysql-test/r/innodb.result:
  Added multi-update-test
mysql-test/r/multi_update.result:
  Added multi-update-test
mysql-test/t/heap.test:
  Test of CREATE TABLE ... type=MEMORY
mysql-test/t/innodb.test:
  Added multi-update-test
mysql-test/t/multi_update.test:
  Added multi-update-test
sql/ha_innodb.h:
  Allow optimzation of multi-table-update also for InnoDB tables
sql/handler.h:
  Allow optimzation of multi-update also for InnoDB tables
sql/key.cc:
  After merge fix
sql/lex.h:
  MEMORY is alias for HEAP
sql/sql_test.cc:
  Fixed wrong printf
sql/sql_update.cc:
  Fixed bug in multi-table-update where a row could be updated several times
sql/sql_yacc.yy:
  MEMORY is alias for HEAP
This commit is contained in:
unknown
2003-03-19 00:45:44 +02:00
parent 21b0873a3c
commit f45236de39
13 changed files with 313 additions and 48 deletions
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146
sql/sql_update.cc
View File

@@ -23,6 +23,8 @@
#include "sql_acl.h"
#include "sql_select.h"
static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields);
/* Return 0 if row hasn't changed */
static bool compare_record(TABLE *table, ulong query_id)
@@ -520,11 +522,12 @@ int multi_update::prepare(List<Item> &not_used_values)
/*
Store first used table in main_table as this should be updated first
This is because we know that no row in this table will be read twice.
Initialize table for multi table
Create temporary tables to store changed values for all other tables
that are updated.
IMPLEMENTATION
- Update first table in join on the fly, if possible
- Create temporary tables to store changed values for all other tables
that are updated (and main_table if the above doesn't hold).
*/
bool
@@ -538,52 +541,113 @@ multi_update::initialize_tables(JOIN *join)
main_table=join->join_tab->table;
trans_safe= transactional_tables= main_table->file->has_transactions();
log_delayed= trans_safe || main_table->tmp_table != NO_TMP_TABLE;
table_to_update= (main_table->file->table_flags() & HA_NOT_MULTI_UPDATE) ?
(TABLE *) 0 : main_table;
/* Create a temporary table for all tables after except main table */
table_to_update= 0;
/* Create a temporary table for keys to all tables, except main table */
for (table_ref= update_tables; table_ref; table_ref=table_ref->next)
{
TABLE *table=table_ref->table;
if (table != table_to_update)
uint cnt= table_ref->shared;
List<Item> temp_fields= *fields_for_table[cnt];
ORDER group;
if (table == main_table) // First table in join
{
uint cnt= table_ref->shared;
ORDER group;
List<Item> temp_fields= *fields_for_table[cnt];
TMP_TABLE_PARAM *tmp_param= tmp_table_param+cnt;
/*
Create a temporary table to store all fields that are changed for this
table. The first field in the temporary table is a pointer to the
original row so that we can find and update it
*/
/* ok to be on stack as this is not referenced outside of this func */
Field_string offset(table->file->ref_length, 0, "offset",
table, 1);
if (temp_fields.push_front(new Item_field(((Field *) &offset))))
DBUG_RETURN(1);
/* Make an unique key over the first field to avoid duplicated updates */
bzero((char*) &group, sizeof(group));
group.asc= 1;
group.item= (Item**) temp_fields.head_ref();
tmp_param->quick_group=1;
tmp_param->field_count=temp_fields.elements;
tmp_param->group_parts=1;
tmp_param->group_length= table->file->ref_length;
if (!(tmp_tables[cnt]=create_tmp_table(thd,
tmp_param,
temp_fields,
(ORDER*) &group, 0, 0, 0,
TMP_TABLE_ALL_COLUMNS)))
DBUG_RETURN(1);
tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE);
if (safe_update_on_fly(join->join_tab, &temp_fields))
{
table_to_update= main_table; // Update table on the fly
continue;
}
}
TMP_TABLE_PARAM *tmp_param= tmp_table_param+cnt;
/*
Create a temporary table to store all fields that are changed for this
table. The first field in the temporary table is a pointer to the
original row so that we can find and update it
*/
/* ok to be on stack as this is not referenced outside of this func */
Field_string offset(table->file->ref_length, 0, "offset",
table, 1);
if (temp_fields.push_front(new Item_field(((Field *) &offset))))
DBUG_RETURN(1);
/* Make an unique key over the first field to avoid duplicated updates */
bzero((char*) &group, sizeof(group));
group.asc= 1;
group.item= (Item**) temp_fields.head_ref();
tmp_param->quick_group=1;
tmp_param->field_count=temp_fields.elements;
tmp_param->group_parts=1;
tmp_param->group_length= table->file->ref_length;
if (!(tmp_tables[cnt]=create_tmp_table(thd,
tmp_param,
temp_fields,
(ORDER*) &group, 0, 0, 0,
TMP_TABLE_ALL_COLUMNS)))
DBUG_RETURN(1);
tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE);
}
DBUG_RETURN(0);
}
/*
Check if table is safe to update on fly
SYNOPSIS
safe_update_on_fly
join_tab How table is used in join
fields Fields that are updated
NOTES
We can update the first table in join on the fly if we know that
a row in this tabel will never be read twice. This is true under
the folloing conditions:
- We are doing a table scan and the data is in a separate file (MyISAM) or
if we don't update a clustered key.
- We are doing a range scan and we don't update the scan key or
the primary key for a clustered table handler.
WARNING
This code is a bit dependent of how make_join_readinfo() works.
RETURN
0 Not safe to update
1 Safe to update
*/
static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields)
{
TABLE *table= join_tab->table;
switch (join_tab->type) {
case JT_SYSTEM:
case JT_CONST:
case JT_EQ_REF:
return 1; // At most one matching row
case JT_REF:
return !check_if_key_used(table, join_tab->ref.key, *fields);
case JT_ALL:
/* If range search on index */
if (join_tab->quick)
return !check_if_key_used(table, join_tab->quick->index,
*fields);
/* If scanning in clustered key */
if ((table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->primary_key < MAX_KEY)
return !check_if_key_used(table, table->primary_key, *fields);
return 1;
default:
break; // Avoid compler warning
}
return 0;
}
multi_update::~multi_update()
{