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4.1 repository of svoj. When svoj does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html
ChangeSet@stripped, 2006-12-20 19:08:28+04:00, svoj@stripped +1 -0
Merge mysql.com:/home/svoj/devel/bk/mysql-4.1-engines
into mysql.com:/home/svoj/devel/mysql/BUG21310/mysql-4.1-engines
MERGE: 1.2529.13.1
sql/sql_update.cc@stripped, 2006-12-20 19:08:24+04:00, svoj@stripped +0 -0
Auto merged
MERGE: 1.157.1.1
# This is a BitKeeper patch. What follows are the unified diffs for the
# set of deltas contained in the patch. The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User: svoj
# Host: april.(none)
# Root: /home/svoj/devel/mysql/BUG21310/mysql-4.1-engines/RESYNC
--- 1.158/sql/sql_update.cc 2006-12-20 19:08:31 +04:00
+++ 1.159/sql/sql_update.cc 2006-12-20 19:08:31 +04:00
@@ -23,8 +23,6 @@
#include "mysql_priv.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)
@@ -846,27 +844,69 @@ int multi_update::prepare(List<Item> &no
for (i=0 ; i < table_count ; i++)
set_if_bigger(max_fields, fields_for_table[i]->elements);
copy_field= new Copy_field[max_fields];
+ DBUG_RETURN(thd->is_fatal_error != 0);
+}
- /*
- Mark all copies of tables that are updates to ensure that
- init_read_record() will not try to enable a cache on them
- The problem is that for queries like
+/*
+ Check if table is safe to update on fly
- UPDATE t1, t1 AS t2 SET t1.b=t2.c WHERE t1.a=t2.a;
+ SYNOPSIS
+ safe_update_on_fly()
+ thd Thread handler
+ join_tab How table is used in join
+ all_tables List of tables
+ fields Fields that are updated
- the row buffer may contain things that doesn't match what is on disk
- which will cause an error when reading a row.
- (This issue is mostly relevent for MyISAM tables)
- */
- for (table_ref= all_tables; table_ref; table_ref=table_ref->next)
- {
- TABLE *table=table_ref->table;
- if ((tables_to_update & table->map) &&
- mysql_lock_have_duplicate(thd, table, update_tables))
- table->no_cache= 1; // Disable row cache
+ NOTES
+ We can update the first table in join on the fly if we know that
+ a row in this table will never be read twice. This is true under
+ the following 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.
+
+ - Table is not joined to itself.
+
+ 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(THD *thd, JOIN_TAB *join_tab,
+ TABLE_LIST *all_tables, List<Item> *fields)
+{
+ TABLE *table= join_tab->table;
+ /* First check if a table is not joined to itself. */
+ if (mysql_lock_have_duplicate(thd, table, all_tables))
+ return 0;
+ 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
}
- DBUG_RETURN(thd->is_fatal_error != 0);
+ return 0;
}
@@ -905,7 +945,7 @@ multi_update::initialize_tables(JOIN *jo
table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
if (table == main_table) // First table in join
{
- if (safe_update_on_fly(join->join_tab, &temp_fields))
+ if (safe_update_on_fly(thd, join->join_tab, all_tables, &temp_fields))
{
table_to_update= main_table; // Update table on the fly
continue;
@@ -949,59 +989,6 @@ multi_update::initialize_tables(JOIN *jo
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;
}
| Thread |
|---|
| • bk commit into 4.1 tree (svoj:1.2585) | Sergey Vojtovich | 20 Dec |
