ddl: the region which presplit at create table, was different on table and partition table

[knull-cn]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

test case : presplit regions when create partition table

-- create table with partitions ;
CREATE TABLE sbtest0000(
  id bigint,
  k bigint DEFAULT '0' NOT NULL,
  c CHAR(120) DEFAULT '' NOT NULL,
  pad CHAR(60) DEFAULT '' NOT NULL,
  UNIQUE KEY uk(id),
  key idx0(k,c),
  key idx1(c)
)SHARD_ROW_ID_BITS=3 PRE_SPLIT_REGIONS=2
PARTITION BY RANGE(id)(PARTITION p VALUES LESS THAN (MAXVALUE));
-- show regions for table;
show table sbtest0000 regions;

test case : presplit regions when create normal table

-- create table ;
CREATE TABLE sbtest1111(
  id bigint,
  k bigint DEFAULT '0' NOT NULL,
  c CHAR(120) DEFAULT '' NOT NULL,
  pad CHAR(60) DEFAULT '' NOT NULL,
  UNIQUE KEY uk(id),
  key idx0(k,c),
  key idx1(c)
)SHARD_ROW_ID_BITS=3 PRE_SPLIT_REGIONS=2;
-- show regions for table;
show table sbtest1111 regions;

2. What did you expect to see? (Required)

the regions splited same numbers

3. What did you see instead (Required)

normal table, the index was splited ,and record was splited to 4 regions;
partition table, all the data for partition table was splited to 4 regions (index was not splited).

4. What is your TiDB version? (Required)

[Defined2014]

Normal tables do not support presplit indexes too. Instead, just let each index has a separate region. Maybe we could change partition table same as normal table.