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The goal of this FLIP is to address the shortcomings mentioned above and make the APIs in TableEnvironment & Table more clear and stable. This FLIP won't support multiline statements which needs more discussion in further FLIP. (There have been some conclusions, please see the appendix.)

Public Interfaces

executeSqlWe We propose to deprecate the following methods:

TableEnvironment.sqlUpdate(String)
TableEnvironment.insertInto(String, Table)
TableEnvironment.execute(String)
TableEnvironment.explain(boolean)
TableEnvironment.fromTableSource(TableSource<?>)
Table.insertInto(String)

meanwhile, we propose to introduce the following new methods:

Code Block

language	java
title	New methods in TableEnvironment

interface TableEnvironment {
    // execute the given single statement, and return the execution result.
	TableResult executeSql(String statement);
    
    // get the AST and the execution plan for the given single statement (DQL, DML)
    String explainSql(String statement, ExplainDetail... extraDetails);

    // create a StatementSet instance which can add DML statements or Tables
    // to the set and explain or execute them as a batch.
    StatementSet createStatementSet();
}

Code Block

language	java
title	New methods in Table

interface Table {
    // write the Table to a TableSink that was registered
    // under the specified path.
	TableResult executeInsert(String tablePath);
    
    // write the Table to a TableSink that was registered
    // under the specified path.
    TableResult executeInsert(String tablePath, boolean overwrite);

    // create a StatementSet instance which can add DML statements or Tables
    // to the set and explain or execute them as a batch.
    String explain(ExplainDetail... extraDetails);

    // get the contents of the current table.
    TableResult execute();
}

Code Block

language	java
title	New class: TableResult

interface TableResult {
     // return JobClient if a Flink job is submitted
     // (for DML/DQL statement), else return empty (e.g. for DDL).
    Optional<JobClient> getJobClient();

    // return the schema of the result
	TableSchema getTableSchema();
    
    // return the ResultKind which can avoid custom parsing of
    // an "OK" row in programming
    ResultKind getResultKind();

    // get the row contents as an iterable rows
    Iterator<Row> collect();

    // print the result contents
    void print();
}

Code Block

language	java
title	New class: ResultKind

public enum ResultKind {
    // for DDL, DCL and statements with a simple "OK" 
	SUCCESS,

    // rows with important content are available (DML, DQL) 
    SUCCESS_WITH_CONTENT
}

Code Block

language	java
title	New class: StatementSet

interface StatementSet  {
    // add single INSERT statement into the set
    StatementSet addInsertSql(String statement);

    // add Table with the given sink table name to the set
    StatementSet addInsert(String targetPath, Table table);

    // add Table with the given sink table name to the set
	StatementSet addInsert(String targetPath, Table table, boolean overwrite);

    // returns the AST and the execution plan to compute 
    // the result of all statements and Tables
    String explain(ExplainDetail... extraDetails);

    // execute all statements and Tables as a batch
    TableResult execute();
}

Code Block

language	java
title	New class: ExplainDetail

public enum ExplainDetail {
   STATE_SIZE_ESTIMATE,
   UID,
   HINTS,
   ...
}

For current messy Flink table program trigger point, we propose that: for TableEnvironment and StreamTableEnvironment, you must use `TableEnvironment.execute()` to trigger table program execution, once you convert the table program to a DataStream program (through `toAppendStream` or `toRetractStream` method), you must use `StreamExecutionEnvironment.execute` to trigger the DataStream program.
Similar rule for BatchTableEnvironment, you must use `TableEnvironment.execute()` to trigger batch table program execution, once you convert the table program (through `toDataSet` method) to a DataSet program, you must use `ExecutionEnvironment.execute` to trigger the DataSet program.

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Versions Compared

Old Version 42

New Version 43

Key

Public Interfaces