Is the phrase "support for cold data backup" in this document incorrect?

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This topic has been translated from a Chinese forum by GPT and might contain errors.

Original topic: 此处文档内的 ”支持数据冷备份“ 是否表述有误?

| username: 滴滴嗒嘀嗒

Overview of Data Migration Tools | PingCAP Documentation Center

| username: xfworld | Original post link

That’s right, BR is cold backup.

| username: 滴滴嗒嘀嗒 | Original post link

Take a look at this post
About br “supporting cold data backup to external storage” - :ringer_planet: TiDB Technical Issues / Backup & Data Migration - TiDB Q&A Community (asktug.com)

| username: 像风一样的男子 | Original post link

It’s hot standby physical backup, right?

| username: xfworld | Original post link

Are you referring to cold backup as copying physical files?

BR is essentially a physical backup mechanism, so calling it cold backup is not an issue.

From another perspective, what kind of cold backup are you expecting?

| username: 滴滴嗒嘀嗒 | Original post link

What I expect from a cold backup is to shut down the database system and then run the backup command. This way, it prevents data from being written during the backup process, which could affect the final backup result. For example, if I run the backup command at time A, the data in the database at that moment is A, and I expect the backup copy to also contain data A. If data B is written to the database during the backup process, then the final backup copy might contain A+B. So, my understanding is that a cold backup can avoid such issues.

BR is not a physical file copy either, right?

| username: zhanggame1 | Original post link

In the 303 course, there is a clear definition of cold backup:


BR is a hot backup

| username: xfworld | Original post link

Well, snapshot data

The generated data is meta Data + Data Rowset, which is still in physical form.

| username: 滴滴嗒嘀嗒 | Original post link

Does the downtime here mean that all components in the cluster are in a normal state? I tried shutting down all TiDB instances, but the BR backup command was still able to run successfully.

| username: 像风一样的男子 | Original post link

BR backup is a hot backup. During the backup, it needs to connect to PD and KV. If PD and KV are down, the backup will definitely fail. If only TiDB is down, the backup can succeed.

| username: 滴滴嗒嘀嗒 | Original post link

In that case, the documentation does indeed have some issues with its wording.

| username: system | Original post link

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