This document describes the query statements supported in the read-only analysis engine and related instructions.
Object Permission Description
In the read-only analysis engine, only data of objects that have been fully loaded into the engine can be queried. To query data, the SELECT permission of the corresponding data table is required. If you do not have the permission, apply for object permissions through account management of TencentDB for MySQL. For details, see Modifying Account Permissions. SELECT Statement
In the read-only analysis engine, SELECT statements are mainly used for data queries.
SELECT
[ALL | DISTINCT | DISTINCTROW ]
select_expr [, select_expr] ...
[FROM table_references
[WHERE where_condition]
[GROUP BY {col_name | expr | position}]
[HAVING where_condition]
[WINDOW window_name AS (window_spec)
[, window_name AS (window_spec)] ...]
[ORDER BY {col_name | expr | position}
[ASC | DESC]]
[LIMIT {[offset,] row_count | row_count OFFSET offset}]
The preceding SELECT statement block is supported in the read-only analysis engine. The following section describes the statement units within the complete SELECT statement segment of MySQL that are not supported in the read-only analysis engine:
HIGH_PRIORITY indicates the priority for executing SELECT statements, which does not take effect in the read-only analysis engine. However, if this keyword is included in an SQL statement, it does not affect the execution result.
STRAIGHT_JOIN indicates that the optimizer is forced to join tables based on the order listed in the clause. However, in a read-only analysis engine, the execution plan is selected only based on the columnar execution optimizer of the read-only analysis engine. Therefore, this keyword does not take effect in a read-only analysis engine.
The SQL_SMALL_RESULT, SQL_BIT_RESULT, SQL_BUFFER_RESULT, SQL_NO_CACHE, and SQL_CALC_FOUND_ROWS query options also do not take effect in a read-only analysis engine but do not affect the execution of query statements.
The PARTITION partition_list clause is not supported in the read-only analysis engine, and this option will cause the query execution to fail.
Note：
The WITH ROLLUP syntax is only supported in versions 3.2503.x and later.
FOR UPDATE | Lock IN SHARE MODE and other clause syntaxes are not supported. If such clauses are included in an SQL statement, they do not take effect, but the SQL statement can be executed properly.
into option is not supported. If this keyword is included in an SQL statement, an error occurs when the SQL statement is executed.