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MDEV-11757 KEY_BLOCK_SIZE strangeness when UNCOMPRESSing COMPRESSed I…

…nnoDB tables

in ALTER TABLE ... DROP KEY, ADD KEY, don't forget to compare old
and new keys' block sizes. If they differ - the key definition has changed.
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vuvova committed Feb 22, 2017
1 parent 6a12c05 commit 370cf70136778b4b89bc3d3d2dfc8a35c7f98478
@@ -0,0 +1,47 @@
set global innodb_file_format=barracuda;
create table t1 (
id1 bigint(20) not null,
id2 bigint(20) not null,
primary key (id1),
unique key id2 (id2)
) engine=innodb row_format=compressed key_block_size=8;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`id1` bigint(20) NOT NULL,
`id2` bigint(20) NOT NULL,
PRIMARY KEY (`id1`),
UNIQUE KEY `id2` (`id2`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=8
alter table t1 row_format=dynamic;
Warnings:
Warning 1478 InnoDB: ignoring KEY_BLOCK_SIZE=8 unless ROW_FORMAT=COMPRESSED.
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`id1` bigint(20) NOT NULL,
`id2` bigint(20) NOT NULL,
PRIMARY KEY (`id1`),
UNIQUE KEY `id2` (`id2`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=DYNAMIC KEY_BLOCK_SIZE=8
alter table t1 key_block_size=0;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`id1` bigint(20) NOT NULL,
`id2` bigint(20) NOT NULL,
PRIMARY KEY (`id1`) KEY_BLOCK_SIZE=8,
UNIQUE KEY `id2` (`id2`) KEY_BLOCK_SIZE=8
) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=DYNAMIC
alter table t1 drop primary key, add primary key (id1),
drop key id2, add unique (id2);
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`id1` bigint(20) NOT NULL,
`id2` bigint(20) NOT NULL,
PRIMARY KEY (`id1`),
UNIQUE KEY `id2` (`id2`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=DYNAMIC
drop table t1;
set global innodb_file_format=default;
@@ -0,0 +1,23 @@
#
# MDEV-11757 KEY_BLOCK_SIZE strangeness when UNCOMPRESSing COMPRESSed InnoDB tables
#
source include/have_innodb.inc;
set global innodb_file_format=barracuda;

create table t1 (
id1 bigint(20) not null,
id2 bigint(20) not null,
primary key (id1),
unique key id2 (id2)
) engine=innodb row_format=compressed key_block_size=8;
show create table t1;
alter table t1 row_format=dynamic;
show create table t1;
alter table t1 key_block_size=0;
show create table t1;
alter table t1 drop primary key, add primary key (id1),
drop key id2, add unique (id2);
show create table t1;
drop table t1;

set global innodb_file_format=default;
@@ -4209,7 +4209,7 @@ enum_alter_inplace_result
handler::check_if_supported_inplace_alter(TABLE *altered_table,
Alter_inplace_info *ha_alter_info)
{
DBUG_ENTER("check_if_supported_alter");
DBUG_ENTER("handler::check_if_supported_inplace_alter");

HA_CREATE_INFO *create_info= ha_alter_info->create_info;

@@ -6429,6 +6429,9 @@ static bool fill_alter_inplace_info(THD *thd,
new_key->user_defined_key_parts))
goto index_changed;

if (table_key->block_size != new_key->block_size)
goto index_changed;

if (engine_options_differ(table_key->option_struct, new_key->option_struct,
table->file->ht->index_options))
goto index_changed;
@@ -2179,6 +2179,74 @@ uint ha_myisam::checksum() const
}


enum_alter_inplace_result
ha_myisam::check_if_supported_inplace_alter(TABLE *new_table,
Alter_inplace_info *alter_info)
{
DBUG_ENTER("ha_myisam::check_if_supported_inplace_alter");

const uint readd_index= Alter_inplace_info::ADD_INDEX |
Alter_inplace_info::DROP_INDEX;
const uint readd_unique= Alter_inplace_info::ADD_UNIQUE_INDEX |
Alter_inplace_info::DROP_UNIQUE_INDEX;
const uint readd_pk= Alter_inplace_info::ADD_PK_INDEX |
Alter_inplace_info::DROP_PK_INDEX;

const uint op= alter_info->handler_flags;

/*
ha_myisam::open() updates table->key_info->block_size to be the actual
MYI index block size, overwriting user-specified value (if any).
So, the server can not reliably detect whether ALTER TABLE changes
key_block_size or not, it might think the block size was changed,
when it wasn't, and in this case the server will recreate (drop+add)
the index unnecessary. Fix it.
*/

if (table->s->keys == new_table->s->keys &&
((op & readd_pk) == readd_pk ||
(op & readd_unique) == readd_unique ||
(op & readd_index) == readd_index))
{
for (uint i=0; i < table->s->keys; i++)
{
KEY *old_key= table->key_info + i;
KEY *new_key= new_table->key_info + i;

if (old_key->block_size == new_key->block_size)
DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED); // must differ somewhere else

if (new_key->block_size && new_key->block_size != old_key->block_size)
DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED); // really changed

/* any difference besides the block_size, and we give up */
if (old_key->key_length != new_key->key_length ||
old_key->flags != new_key->flags ||
old_key->user_defined_key_parts != new_key->user_defined_key_parts ||
old_key->algorithm != new_key->algorithm ||
strcmp(old_key->name, new_key->name))
DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);

for (uint j= 0; j < old_key->user_defined_key_parts; j++)
{
KEY_PART_INFO *old_kp= old_key->key_part + j;
KEY_PART_INFO *new_kp= new_key->key_part + j;
if (old_kp->offset != new_kp->offset ||
old_kp->null_offset != new_kp->null_offset ||
old_kp->length != new_kp->length ||
old_kp->fieldnr != new_kp->fieldnr ||
old_kp->key_part_flag != new_kp->key_part_flag ||
old_kp->type != new_kp->type ||
old_kp->null_bit != new_kp->null_bit)
DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);
}
}
alter_info->handler_flags &= ~(readd_pk | readd_unique | readd_index);
}
DBUG_RETURN(handler::check_if_supported_inplace_alter(new_table, alter_info));
}


bool ha_myisam::check_if_incompatible_data(HA_CREATE_INFO *info,
uint table_changes)
{
@@ -138,6 +138,8 @@ class ha_myisam: public handler
int optimize(THD* thd, HA_CHECK_OPT* check_opt);
int assign_to_keycache(THD* thd, HA_CHECK_OPT* check_opt);
int preload_keys(THD* thd, HA_CHECK_OPT* check_opt);
enum_alter_inplace_result check_if_supported_inplace_alter(TABLE *new_table,
Alter_inplace_info *alter_info);
bool check_if_incompatible_data(HA_CREATE_INFO *info, uint table_changes);
#ifdef HAVE_QUERY_CACHE
my_bool register_query_cache_table(THD *thd, char *table_key,

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