EXPLAIN PLAN FOR<query_statement_or_insert_statement> 1. 实际案例: 复制 public class Explain_Test{public static void main(String[]args)throws Exception{FlinkEnv flinkEnv=FlinkEnvUtils.getStreamTableEnv(args);flinkEnv.env().setParallelism(1);String sql="CREATE TABLE source_table (\n"+" user_i...
⭐ SQL 语法标准: 代码语言:javascript 复制 EXPLAIN PLAN FOR <query_statement_or_insert_statement> ⭐ 实际案例: 代码语言:javascript 复制 public class Explain_Test { public static void main(String[] args) throws Exception { FlinkEnv flinkEnv = FlinkEnvUtils.getStreamTableEnv(args); flinkEnv....
1.1.2. EXPLAIN类型 EXPLAIN 常用语句类型如下: 1. EXPLAIN AST:用于查看抽象语法树(Abstract Syntax Tree)。支持查看所有类型的语句,不光是SELECT语句。 2. EXPLAIN SYNTAX:查询经过AST层优化后的 SQL 语句; 3. EXPLAIN PLAN:用于查看执行计划(Execution Plan),等价于直接使用 EXPLAIN。可以指定五个参数; ① head...
Your goals areto recognize the aspects of the EXPLAIN plan that indicate a query is optimizedwell, and to learn the SQL syntax and indexing techniques to improve the planif you see some inefficient operations. 查看执行计划示例: mysql> explain select * from user where User='root'; +---+--...
在clickhouse 20.6 版本之前要查看 SQL 语句的执行计划需要设置日志级别为 trace 才能可以看到,并且只能真正执行 sql,在执行日志里面查看。在 20.6 版本引入了原生的执行计划的语法。在 20.6.3 版本成为正式版本的功能。 EXPLAIN [AST | SYNTAX | PLAN | PIPELINE] [setting =value, ...] SELECT ... [FORMAT ...
在clickhouse 20.6 版本之前要查看 SQL 语句的执行计划需要设置日志级别为 trace 才能可以看到,并且只能真正执行 sql,在执行日志里面查看。在 20.6 版本引入了原生的执行计划的语法。在 20.6.3 版本成为正式版本的功能。 EXPLAIN EXPLAIN [AST | SYNTAX | PLAN | PIPELINE] [setting = value,...] SELECT ... ...
for (String innerSql : sql.split(";")) { TableResult tableResult = flinkEnv.streamTEnv().executeSql(innerSql); tableResult.print(); } } } 上述代码执行结果如下: 1. 抽象语法树 == Abstract Syntax Tree == LogicalSink(table=[default_catalog.default_database.sink_table], fields=[user_id...
Plan information cannot be collected for SQL statements that failed to be executed. Data in PLAN_TABLE is in a session-level lifecycle. Sessions are isolated from users, and therefore users can only view the data of the current session and current user. PLAN_TABLE cannot be joined with GDS ...
See Also: For the syntax of the EXPLAIN PLAN command, see the Oracle8 SQL Reference.IntroductionThe EXPLAIN PLAN command displays the execution plan chosen by the Oracle optimizer for SELECT, UPDATE, INSERT, and DELETE statements. A statement's execution plan is the sequence of operations that ...
Query Plan --- SELECT STATEMENT [CHOOSE] Cost=1 INDEX UNIQUE SCAN EMP_I1 Indexes are presorted so sorting may be unnecessary if the sort order required is the same as the index. e.g. SQL> explain plan for select empno,ename from emp where empno > 7876 order by empno; Query Plan --...