MDEV-36032 Check whether a table can be a sequence when ALTERed with SEQUENCE=1

To check the rows, the table needs to be opened. To that end, and like
MDEV-36038, we force COPY algorithm on ALTER TABLE ... SEQUENCE=1.
This also results in checking the sequence state / metadata.

The table structure was already validated before this patch.

Author: mariadb-YuchenPei

mysql-test/suite/sql_sequence/alter.result

@@ -419,3 +419,73 @@ DROP SEQUENCE s2;
 #
 # End of 10.6 tests
 #
+#
+# MDEV-36032 Check when doing ALTER TABLE table_name sequence=1 that table can be a sequence
+#
+create sequence s;
+alter table s sequence=0;
+insert into s values (3,1,9223372036854775806,1,1,1000,0,0);
+alter table s sequence=1;
+ERROR HY000: More than one row in the table
+drop table s;
+create sequence s;
+alter table s sequence=0;
+delete from s;
+insert into s values (2,500,200,1,1,1000,0,0);
+select * from s;
+next_not_cached_value	minimum_value	maximum_value	start_value	increment	cache_size	cycle_option	cycle_count
+2	500	200	1	1	1000	0	0
+alter table s sequence=1;
+ERROR HY000: Sequence 'test.s' has out of range value for options
+check table s;
+Table	Op	Msg_type	Msg_text
+test.s	check	status	OK
+select * from s;
+next_not_cached_value	minimum_value	maximum_value	start_value	increment	cache_size	cycle_option	cycle_count
+2	500	200	1	1	1000	0	0
+check table s;
+Table	Op	Msg_type	Msg_text
+test.s	check	status	OK
+drop table s;
+CREATE TABLE `s` (
+# `next_not_cached_value` bigint(21) NOT NULL,
+`minimum_value` bigint(21) NOT NULL,
+`maximum_value` bigint(21) NOT NULL,
+`start_value` bigint(21) NOT NULL COMMENT 'start value when sequences is created or value if RESTART is used',
+`increment` bigint(21) NOT NULL COMMENT 'increment value',
+`cache_size` bigint(21) unsigned NOT NULL,
+`cycle_option` tinyint(1) unsigned NOT NULL COMMENT '0 if no cycles are allowed, 1 if the sequence should begin a new cycle when maximum_value is passed',
+`cycle_count` bigint(21) NOT NULL COMMENT 'How many cycles have been done'
+) ENGINE=innodb;
+alter table s sequence=1;
+ERROR HY000: Sequence 'test.s' table structure is invalid (Wrong number of columns)
+drop table s;
+create sequence s;
+alter table s drop column next_not_cached_value;
+ERROR HY000: Sequence 'test.s' table structure is invalid (Wrong number of columns)
+drop sequence s;
+CREATE TABLE `s1` (
+`next_not_cached_value` bigint(21) NOT NULL,
+`minimum_value` bigint(21) NOT NULL,
+`maximum_value` bigint(21) NOT NULL,
+`start_value` bigint(21) NOT NULL COMMENT 'start value when sequences is created or value if RESTART is used',
+`increment` bigint(21) NOT NULL COMMENT 'increment value',
+`cache_size` bigint(21) unsigned NOT NULL,
+`cycle_option` tinyint(1) unsigned NOT NULL COMMENT '0 if no cycles are allowed, 1 if the sequence should begin a new cycle when maximum_value is passed',
+`cycle_count` bigint(21) NOT NULL COMMENT 'How many cycles have been done'
+) ENGINE=innodb;
+alter table s1 sequence=1;
+ERROR HY000: Fewer than one row in the table
+alter table s1 sequence=0;
+insert into s1 values (1,1,9223372036854775806,1,1,1000,0,0);
+alter table s1 sequence=1;
+alter table s1 sequence=0;
+insert into s1 values (2,1,9223372036854775806,1,1,1000,0,0);
+alter table s1 sequence=1;
+ERROR HY000: More than one row in the table
+alter table s1 sequence=0;
+insert into s1 values (3,1,9223372036854775806,1,1,1000,0,0);
+alter table s1 sequence=1;
+ERROR HY000: More than one row in the table
+drop table s1;
+# End of 10.11 tests

mysql-test/suite/sql_sequence/alter.test

@@ -295,3 +295,84 @@ DROP SEQUENCE s2;
 --echo #
 --echo # End of 10.6 tests
 --echo #
+
+--echo #
+--echo # MDEV-36032 Check when doing ALTER TABLE table_name sequence=1 that table can be a sequence
+--echo #
+
+## Too many rows
+create sequence s;
+alter table s sequence=0;
+insert into s values (3,1,9223372036854775806,1,1,1000,0,0);
+--error ER_SEQUENCE_TABLE_HAS_TOO_MANY_ROWS
+alter table s sequence=1;
+drop table s;
+
+## Insert a wrong row (min > max)
+create sequence s;
+alter table s sequence=0;
+delete from s;
+insert into s values (2,500,200,1,1,1000,0,0);
+select * from s;
+--error ER_SEQUENCE_INVALID_DATA
+alter table s sequence=1;
+check table s;
+select * from s;
+check table s;
+drop table s;
+
+## Invalid table structure (already implemented before MDEV-36032)
+CREATE TABLE `s` (
+  # `next_not_cached_value` bigint(21) NOT NULL,
+  `minimum_value` bigint(21) NOT NULL,
+  `maximum_value` bigint(21) NOT NULL,
+  `start_value` bigint(21) NOT NULL COMMENT 'start value when sequences is created or value if RESTART is used',
+  `increment` bigint(21) NOT NULL COMMENT 'increment value',
+  `cache_size` bigint(21) unsigned NOT NULL,
+  `cycle_option` tinyint(1) unsigned NOT NULL COMMENT '0 if no cycles are allowed, 1 if the sequence should begin a new cycle when maximum_value is passed',
+  `cycle_count` bigint(21) NOT NULL COMMENT 'How many cycles have been done'
+) ENGINE=innodb;
+--error ER_SEQUENCE_INVALID_TABLE_STRUCTURE
+alter table s sequence=1;
+drop table s;
+
+## Altering a sequence table to a wrong structure is detected (already
+## implemented before MDEV-36032)
+create sequence s;
+--error ER_SEQUENCE_INVALID_TABLE_STRUCTURE
+alter table s drop column next_not_cached_value;
+drop sequence s;
+
+## Create a normal table then alter to sequence
+CREATE TABLE `s1` (
+`next_not_cached_value` bigint(21) NOT NULL,
+`minimum_value` bigint(21) NOT NULL,
+`maximum_value` bigint(21) NOT NULL,
+`start_value` bigint(21) NOT NULL COMMENT 'start value when sequences is created or value if RESTART is used',
+`increment` bigint(21) NOT NULL COMMENT 'increment value',
+`cache_size` bigint(21) unsigned NOT NULL,
+`cycle_option` tinyint(1) unsigned NOT NULL COMMENT '0 if no cycles are allowed, 1 if the sequence should begin a new cycle when maximum_value is passed',
+`cycle_count` bigint(21) NOT NULL COMMENT 'How many cycles have been done'
+) ENGINE=innodb;
+
+--error ER_SEQUENCE_TABLE_HAS_TOO_FEW_ROWS
+alter table s1 sequence=1;
+# (for coverage) alter a non sequence table with sequence=0
+alter table s1 sequence=0;
+insert into s1 values (1,1,9223372036854775806,1,1,1000,0,0);
+alter table s1 sequence=1;
+
+alter table s1 sequence=0;
+insert into s1 values (2,1,9223372036854775806,1,1,1000,0,0);
+--error ER_SEQUENCE_TABLE_HAS_TOO_MANY_ROWS
+alter table s1 sequence=1;
+
+# (for coverage) alter a non sequence table with sequence=0
+alter table s1 sequence=0;
+insert into s1 values (3,1,9223372036854775806,1,1,1000,0,0);
+--error ER_SEQUENCE_TABLE_HAS_TOO_MANY_ROWS
+alter table s1 sequence=1;
+
+drop table s1;
+
+--echo # End of 10.11 tests

sql/handler.cc

@@ -5454,6 +5454,9 @@ handler::check_if_supported_inplace_alter(TABLE *altered_table,
       (table->s->row_type != create_info->row_type))
     DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);
 
+  if (create_info->sequence)
+    DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);
+
   uint table_changes= (ha_alter_info->handler_flags &
                        ALTER_COLUMN_TYPE_CHANGE_BY_ENGINE) ?
     IS_EQUAL_PACK_LENGTH : IS_EQUAL_YES;

sql/share/errmsg-utf8.txt

@@ -10758,3 +10758,7 @@ ER_CM_OPTION_MISSING_REQUIREMENT
         eng "CHANGE MASTER TO option '%s=%s' is missing requirement %s"
 ER_SLAVE_STATEMENT_TIMEOUT 70100
         eng "Slave log event execution was interrupted (slave_max_statement_time exceeded)"
+ER_SEQUENCE_TABLE_HAS_TOO_FEW_ROWS
+        eng "Fewer than one row in the table"
+ER_SEQUENCE_TABLE_HAS_TOO_MANY_ROWS
+        eng "More than one row in the table"

sql/sql_table.cc

@@ -12154,6 +12154,16 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to, bool ignore,
   Create_field *def;
   copy_end=copy;
   to->s->default_fields= 0;
+  if (to->s->table_type == TABLE_TYPE_SEQUENCE &&
+      from->file->ha_table_flags() & HA_STATS_RECORDS_IS_EXACT &&
+      from->file->stats.records != 1)
+  {
+    if (from->file->stats.records > 1)
+      my_error(ER_SEQUENCE_TABLE_HAS_TOO_MANY_ROWS, MYF(0));
+    else
+      my_error(ER_SEQUENCE_TABLE_HAS_TOO_FEW_ROWS, MYF(0));
+    goto err;
+  }
   for (Field **ptr=to->field ; *ptr ; ptr++)
   {
     def=it++;
@@ -12337,6 +12347,12 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to, bool ignore,
       else
         to->next_number_field->reset();
     }
+    if (to->s->table_type == TABLE_TYPE_SEQUENCE && found_count == 1)
+    {
+      my_error(ER_SEQUENCE_TABLE_HAS_TOO_MANY_ROWS, MYF(0));
+      error= 1;
+      break;
+    }
     error= to->file->ha_write_row(to->record[0]);
     to->auto_increment_field_not_null= FALSE;
     if (unlikely(error))
@@ -12356,6 +12372,12 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to, bool ignore,
     thd->get_stmt_da()->inc_current_row_for_warning();
   }
 
+  if (to->s->table_type == TABLE_TYPE_SEQUENCE && found_count == 0)
+  {
+    my_error(ER_SEQUENCE_TABLE_HAS_TOO_FEW_ROWS, MYF(0));
+    error= 1;
+  }
+
   THD_STAGE_INFO(thd, stage_enabling_keys);
   thd_progress_next_stage(thd);