From 6fdbe91570904c04618bf03c614bf34f0ae1b98c Mon Sep 17 00:00:00 2001 From: Grace Cai Date: Wed, 2 Apr 2025 22:17:07 +0800 Subject: [PATCH 1/4] Add temp.md --- temp.md | 1 + 1 file changed, 1 insertion(+) create mode 100644 temp.md diff --git a/temp.md b/temp.md new file mode 100644 index 0000000000000..af27ff4986a7b --- /dev/null +++ b/temp.md @@ -0,0 +1 @@ +This is a test file. \ No newline at end of file From 9b48e4d08f4995eef936bc80001b663d80bc3aa9 Mon Sep 17 00:00:00 2001 From: Grace Cai Date: Wed, 2 Apr 2025 22:17:12 +0800 Subject: [PATCH 2/4] Delete temp.md --- temp.md | 1 - 1 file changed, 1 deletion(-) delete mode 100644 temp.md diff --git a/temp.md b/temp.md deleted file mode 100644 index af27ff4986a7b..0000000000000 --- a/temp.md +++ /dev/null @@ -1 +0,0 @@ -This is a test file. \ No newline at end of file From ab3620e718bc24026762a1302f2a18525c682e72 Mon Sep 17 00:00:00 2001 From: qiancai Date: Tue, 8 Apr 2025 17:27:36 +0800 Subject: [PATCH 3/4] Update tiflash-upgrade-guide.md --- tiflash-upgrade-guide.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tiflash-upgrade-guide.md b/tiflash-upgrade-guide.md index ad7c9000a168f..3c45ed0b39dab 100644 --- a/tiflash-upgrade-guide.md +++ b/tiflash-upgrade-guide.md @@ -128,6 +128,10 @@ Starting from v7.4, to reduce the read and write amplification generated during Starting from v8.4, the underlying storage format of TiFlash is updated to support [vector search](/vector-search/vector-search-overview.md). Therefore, after TiFlash is upgraded to v8.4 or a later version, in-place downgrading to the original version is not supported. +## From v8.x to v9.0 or a later version + +Starting from v9.0, TiFlash optimizes the storage format of string data to improve the string read and write performance. Therefore, after TiFlash is upgraded to v9.0 or a later version, in-place downgrading to the original version is not supported. + **Workaround for downgrading TiFlash in testing or other special scenarios** To downgrade TiFlash in testing or other special scenarios, you can forcibly scale in the target TiFlash node and then replicate data from TiKV again. For detailed steps, see [Scale in a TiFlash cluster](/scale-tidb-using-tiup.md#scale-in-a-tiflash-cluster). From 3e7b490bba898da3d03941e1ba2cba073d7f4c54 Mon Sep 17 00:00:00 2001 From: Grace Cai Date: Wed, 9 Apr 2025 16:17:13 +0800 Subject: [PATCH 4/4] Update tiflash-upgrade-guide.md Co-authored-by: Aolin --- tiflash-upgrade-guide.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tiflash-upgrade-guide.md b/tiflash-upgrade-guide.md index 3c45ed0b39dab..8506a4e1ef41a 100644 --- a/tiflash-upgrade-guide.md +++ b/tiflash-upgrade-guide.md @@ -130,7 +130,7 @@ Starting from v8.4, the underlying storage format of TiFlash is updated to suppo ## From v8.x to v9.0 or a later version -Starting from v9.0, TiFlash optimizes the storage format of string data to improve the string read and write performance. Therefore, after TiFlash is upgraded to v9.0 or a later version, in-place downgrading to the original version is not supported. +Starting from v9.0.0, TiFlash optimizes the storage format of string data to improve the string read and write performance. Therefore, after TiFlash is upgraded to v9.0.0 or a later version, in-place downgrading to the original version is not supported. **Workaround for downgrading TiFlash in testing or other special scenarios**