Add new Index advisor user doc #19867

qw4990 · 2025-01-02T08:11:48Z

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Oreoxmt · 2025-01-02T08:18:22Z

@qw4990 Could you please invite a tech reviewer? Thanks!

index-advisor.md

ti-chi-bot · 2025-01-02T08:38:18Z

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index-advisor.md

songrijie · 2025-01-07T07:28:09Z

index-advisor.md

+
+```sql
+mysql> CREATE TABLE t(a int, b int, c int);
+mysql> RECOMMEND INDEX RUN for "select a, b from t where a=1 and b=1";


Does it command accept "\G" as delimiter? column-style printing improves readability for single output.

songrijie · 2025-01-07T07:40:22Z

index-advisor.md

+mysql> CREATE TABLE t(a int, b int, c int);
+mysql> RECOMMEND INDEX RUN for "select a, b from t where a=1 and b=1";
+----------+-------+------------+---------------+------------+----------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------+---------------------------------+
+| database | table | index_name | index_columns | index_size | reason                                                                                                                           | top_impacted_query                                                                            | create_index_statement          |


If "index_size" is not exact value, better to rename it with "est_index_size".

It's recommended to append meaningful string as suffix of index name, so that we are able to understand it's from index advisor. Name conflict can be avoid as well. For example "idx_..._<trailing 8 chars in plan digest>

index_size is the maximum number of columns an index can have. May be we can rename to reflect that, say "max_index_columns".

songrijie · 2025-01-07T07:44:42Z

index-advisor.md

+----------+-------+------------+---------------+------------+----------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------+---------------------------------+
+| database | table | index_name | index_columns | index_size | reason                                                                                                                           | top_impacted_query                                                                            | create_index_statement          |
+----------+-------+------------+---------------+------------+----------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------+---------------------------------+
+| test     | t     | idx_a_b    | a,b           | 19872      | Column [a b] appear in Equal or Range Predicate clause(s) in query: select `a` , `b` from `test` . `t` where `a` = ? and `b` = ? | [{"Query":"SELECT `a`,`b` FROM `test`.`t` WHERE `a` = 1 AND `b` = 1","Improvement":0.999994}] | CREATE INDEX idx_a_b ON t(a,b); |


We shall explain how we decide "Improvement" later in this section.

songrijie · 2025-01-07T07:55:43Z

index-advisor.md

+
+```sql
+Recommend Index Set <option> = <value>;
+Recommend Index Show;


Can we make this "Recommend Index Show Options"? We'd better reserve "Recommend Index Show " for future usage.

Agree since it is only used to show options.

index-advisor.md

Co-authored-by: Roger Song <[email protected]>

ti-chi-bot · 2025-01-08T08:10:46Z

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qw4990 added 2 commits January 2, 2025 16:09

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qw4990 requested review from songrijie and ghazalfamilyusa January 2, 2025 08:37

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