From 2a3ad19e7191bbc3fbc85a175c2a09ac647a34cb Mon Sep 17 00:00:00 2001 From: Ngo Quoc Dat Date: Thu, 22 Oct 2026 18:22:29 +0700 Subject: [PATCH] docs(databases): how ClickHouse sends long values --- databases/clickhouse.mdx | 2 ++ 1 file changed, 2 insertions(+) diff --git a/databases/clickhouse.mdx b/databases/clickhouse.mdx index 23da4c7..790c96c 100644 --- a/databases/clickhouse.mdx +++ b/databases/clickhouse.mdx @@ -64,6 +64,8 @@ Each request carries a query id and asks for progress in the HTTP headers, so a Grid edits go out as INSERT, `ALTER TABLE … UPDATE`, and `ALTER TABLE … DELETE`. +Values too long for the URL travel inside the statement in the request body, so a long text value or a large import is not held to the server's URL limits. A statement longer than your user's `max_query_size` raises that setting for its own request, unless the user is read-only or a settings constraint caps it lower. + ClickHouse mutations run in the background, so the grid reports the statement as accepted rather than applied, and a large table can take a long time. Watch `SELECT * FROM system.mutations WHERE is_done = 0` for progress.