From 8062fb578c7b6c65d4d24efa28bb47e8c8783ae8 Mon Sep 17 00:00:00 2001 From: Justin de Guzman Date: Sat, 18 Nov 2023 18:38:49 -0800 Subject: [PATCH] [Docs] Recommend ReplacingMergeTree for frequent updates --- docs/en/engines/table-engines/mergetree-family/mergetree.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/docs/en/engines/table-engines/mergetree-family/mergetree.md b/docs/en/engines/table-engines/mergetree-family/mergetree.md index e615c9ad9d3..d250cfd1a08 100644 --- a/docs/en/engines/table-engines/mergetree-family/mergetree.md +++ b/docs/en/engines/table-engines/mergetree-family/mergetree.md @@ -6,7 +6,7 @@ sidebar_label: MergeTree # MergeTree -The `MergeTree` engine and other engines of this family (`*MergeTree`) are the most robust ClickHouse table engines. +The `MergeTree` engine and other engines of this family (`*MergeTree`) are the most common and most robust ClickHouse table engines. Engines in the `MergeTree` family are designed for inserting a very large amount of data into a table. The data is quickly written to the table part by part, then rules are applied for merging the parts in the background. This method is much more efficient than continually rewriting the data in storage during insert. @@ -32,6 +32,8 @@ Main features: The [Merge](/docs/en/engines/table-engines/special/merge.md/#merge) engine does not belong to the `*MergeTree` family. ::: +If you need to update rows frequently, we recommend using the [`ReplacingMergeTree`](/docs/en/engines/table-engines/mergetree-family/replacingmergetree.md). Using `ALTER TALBE my_table UPDATE` to update rows triggers a mutation, which causes parts to be re-written and uses IO/resources. With `ReplacingMergeTree`, you can simply insert the updated rows and the old rows will be replaced according to the table sorting key. + ## Creating a Table {#table_engine-mergetree-creating-a-table} ``` sql