From 164030bc479a50a092b260e173e038ab7cec1b69 Mon Sep 17 00:00:00 2001 From: Ti Chi Robot Date: Tue, 24 Dec 2024 12:19:15 +0800 Subject: [PATCH] Improve usage of `IMPORT FROM SELECT` (#19777) (#19780) --- sql-statements/sql-statement-import-into.md | 1 + 1 file changed, 1 insertion(+) diff --git a/sql-statements/sql-statement-import-into.md b/sql-statements/sql-statement-import-into.md index af96bf76ddf96..dee353d8fba2b 100644 --- a/sql-statements/sql-statement-import-into.md +++ b/sql-statements/sql-statement-import-into.md @@ -49,6 +49,7 @@ The `IMPORT INTO` statement lets you import data to TiDB via the [Physical Impor - `IMPORT INTO ... FROM SELECT` does not support the task management statements such as `SHOW IMPORT JOB(s)` and `CANCEL IMPORT JOB `. - The [temporary directory](https://docs.pingcap.com/tidb/stable/tidb-configuration-file#temp-dir-new-in-v630) of TiDB requires sufficient space to store the entire query result of the `SELECT` statement (configuring the `DISK_QUOTA` option is not supported currently). - Importing historical data using [`tidb_snapshot`](/read-historical-data.md) is not supported. +- Because the syntax of the `SELECT` clause is complex, the `WITH` parameter in `IMPORT INTO` might conflict with it and cause parsing errors, such as `GROUP BY ... [WITH ROLLUP]`. It is recommended to create a view for complex `SELECT` statements and then use `IMPORT INTO ... FROM SELECT * FROM view_name` for importing. Alternatively, you can clarify the scope of the `SELECT` clause with parentheses, such as `IMPORT INTO ... FROM (SELECT ...) WITH ...`. ## Prerequisites for import