From 42069ea2cd9c9fbd79d195fa493087e39b8ec05d Mon Sep 17 00:00:00 2001 From: Grace Cai Date: Tue, 6 Aug 2024 18:32:10 +0800 Subject: [PATCH] partitioned tables: add some restrictions (#18483) --- partitioned-table.md | 6 ++++++ sql-statements/sql-statement-create-table.md | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/partitioned-table.md b/partitioned-table.md index 8733e29bcdba3..7bfe1e7849564 100644 --- a/partitioned-table.md +++ b/partitioned-table.md @@ -1468,6 +1468,12 @@ Partition selection is supported for all types of table partitioning, including This section introduces some restrictions and limitations on partitioned tables in TiDB. +- Using the [`ALTER TABLE ... CHANGE COLUMN`](/sql-statements/sql-statement-change-column.md) statement to change column types of partitioned tables is not supported. +- Using the [`ALTER TABLE ... CACHE`](/cached-tables.md) statement to set partitioned tables to cached tables is not supported. +- [Temporary tables](/temporary-tables.md) in TiDB are **NOT** compatible with partitioned tables. +- Creating a [foreign key](/foreign-key.md) on a partitioned table is not supported. +- The [`ORDER_INDEX(t1_name, idx1_name [, idx2_name ...])`](/optimizer-hints.md#order_indext1_name-idx1_name--idx2_name-) hint does not work for partitioned tables and their related indexes, because indexes on partitioned tables cannot be read in order. + ### Partitioning keys, primary keys and unique keys This section discusses the relationship of partitioning keys with primary keys and unique keys. The rule governing this relationship can be expressed as follows: **Every unique key on the table must use every column in the table's partitioning expression**. This also includes the table's primary key, because it is by definition a unique key. diff --git a/sql-statements/sql-statement-create-table.md b/sql-statements/sql-statement-create-table.md index f9250151c55d3..78be305013231 100644 --- a/sql-statements/sql-statement-create-table.md +++ b/sql-statements/sql-statement-create-table.md @@ -258,7 +258,7 @@ mysql> DESC t1; * The `[ASC | DESC]` in `index_col_name` is currently parsed but ignored (MySQL 5.7 compatible behavior). * The `COMMENT` attribute does not support the `WITH PARSER` option. * TiDB supports 1017 columns in a single table by default and 4096 columns at most. The corresponding number limit in InnoDB is 1017 columns, and the hard limit in MySQL is 4096 columns. For details, see [TiDB Limitations](/tidb-limitations.md). -* For partitioned tables, only Range, Hash and Range Columns (single column) are supported. For details, see [partitioned table](/partitioned-table.md). +* TiDB supports `HASH`, `RANGE`, `LIST`, and `KEY` [partitioning types](/partitioned-table.md#partitioning-types). For an unsupported partition type, TiDB returns `Warning: Unsupported partition type %s, treat as normal table`, where `%s` is the specific unsupported partition type. ## See also