From 2de6fad0a9c2572881ba5f3633f5d3722d27d79c Mon Sep 17 00:00:00 2001 From: Weizhen Wang Date: Wed, 10 Apr 2024 17:06:06 +0800 Subject: [PATCH] *: improve INL_HASH_JOIN document about collation incompatibility Signed-off-by: Weizhen Wang --- optimizer-hints.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/optimizer-hints.md b/optimizer-hints.md index 369020b628aae..5bc8e0fb73f49 100644 --- a/optimizer-hints.md +++ b/optimizer-hints.md @@ -930,9 +930,9 @@ The warning is as follows: In this case, you need to place the hint directly after the `SELECT` keyword. For more details, see the [Syntax](#syntax) section. -### INL_JOIN hint does not take effect due to collation incompatibility +### INL_JOIN, INL_HASH_JOIN hint does not take effect due to collation incompatibility -When the collation of the join key is incompatible between two tables, the `IndexJoin` operator cannot be utilized to execute the query. In this case, the [`INL_JOIN` hint](#inl_joint1_name--tl_name-) does not take effect. For example: +When the collation of the join key is incompatible between two tables, the `IndexJoin` operator cannot be utilized to execute the query. In this case, the [`INL_JOIN` hint](#inl_joint1_name--tl_name-) or [`INL_HASH_JOIN` hint](#inl_hash_join) does not take effect. For example: ```sql CREATE TABLE t1 (k varchar(8), key(k)) COLLATE=utf8mb4_general_ci; @@ -955,7 +955,7 @@ The execution plan is as follows: 5 rows in set, 1 warning (0.00 sec) ``` -In the preceding statements, the collations of `t1.k` and `t2.k` are incompatible (`utf8mb4_general_ci` and `utf8mb4_bin` respectively), which prevents the `INL_JOIN` or `TIDB_INLJ` hint from taking effect. +In the preceding statements, the collations of `t1.k` and `t2.k` are incompatible (`utf8mb4_general_ci` and `utf8mb4_bin` respectively), which prevents the `INL_JOIN`, `TIDB_INLJ` or `INL_HASH_JOIN` hint from taking effect. ```sql SHOW WARNINGS;