This is for oracle only. Does not appear to be an issue with other DBs. When you upgrade hive schema from 2.1.0 to hive 3.0.0, the width of TXN_COMPONENTS.TC_TABLE is 256 and COMPLETED_TXN_COMPONENTS.CTC_TABLE is 128.
But if you install hive 3.0 schema directly, their widths are 128 and 256 respectively. This is consistent with schemas for other databases.