tidb, I_S: TABLE_ID size is 21 or 64

[shawn0915]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

https://github.com/pingcap/tidb/blob/master/pkg/infoschema/tables.go#L1379

var tableTableTiFlashTablesCols = []columnInfo{
{name: "TABLE_ID", tp: mysql.TypeLonglong, size: 64},

https://github.com/pingcap/tidb/blob/master/pkg/infoschema/tables.go#L1436

var tableTableTiFlashSegmentsCols = []columnInfo{
{name: "TABLE_ID", tp: mysql.TypeLonglong, size: 64},

ref asktug topic: https://asktug.com/t/topic/1015931

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

size is 21? plz confirm.

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

master

[shawn0915]

@lidezhu PTAL