Hi Godfrey,
thanks for starting the discussion on the mailing list. And sorry again
for the late reply to FLIP-84. I have updated the Google doc one more
time to incorporate the offline discussions.
From Dawid's and my view, it is fine to postpone the multiline support
to a separate method. This can be future work even though we will need
it rather soon.
If there are no objections, I suggest to update the FLIP-84 again and
have another voting process.
Thanks,
Timo
On 25.03.20 11:17, godfrey he wrote:
Hi community,
Timo, Fabian and Dawid have some feedbacks about FLIP-84[1]. The feedbacks
are all about new introduced methods. We had a discussion yesterday, and
most of feedbacks have been agreed upon. Here is the conclusions:
*1. about proposed methods in `TableEnvironment`:*
the original proposed methods:
TableEnvironment.createDmlBatch(): DmlBatch
TableEnvironment.executeStatement(String statement): ResultTable
the new proposed methods:
// we should not use abbreviations in the API, and the term "Batch" is
easily confused with batch/streaming processing
TableEnvironment.createStatementSet(): StatementSet
// every method that takes SQL should have `Sql` in its name
// supports multiline statement ???
TableEnvironment.executeSql(String statement): TableResult
// new methods. supports explaining DQL and DML
TableEnvironment.explainSql(String statement, ExplainDetail... details):
String
*2. about proposed related classes:*
the original proposed classes:
interface DmlBatch {
void addInsert(String insert);
void addInsert(String targetPath, Table table);
ResultTable execute() throws Exception ;
String explain(boolean extended);
}
public interface ResultTable {
TableSchema getResultSchema();
Iterable<Row> getResultRows();
}
the new proposed classes:
interface StatementSet {
// every method that takes SQL should have `Sql` in its name
// return StatementSet instance for fluent programming
addInsertSql(String statement): StatementSet
// return StatementSet instance for fluent programming
addInsert(String tablePath, Table table): StatementSet
// new method. support overwrite mode
addInsert(String tablePath, Table table, boolean overwrite):
StatementSet
explain(): String
// new method. supports adding more details for the result
explain(ExplainDetail... extraDetails): String
// throw exception ???
execute(): TableResult
}
interface TableResult {
getTableSchema(): TableSchema
// avoid custom parsing of an "OK" row in programming
getResultKind(): ResultKind
// instead of `get` make it explicit that this is might be triggering
an expensive operation
collect(): Iterable<Row>
// for fluent programming
print(): Unit
}
enum ResultKind {
SUCCESS, // for DDL, DCL and statements with a simple "OK"
SUCCESS_WITH_CONTENT, // rows with important content are available
(DML, DQL)
}
*3. new proposed methods in `Table`*
`Table.insertInto()` will be deprecated, and the following methods are
introduced:
Table.executeInsert(String tablePath): TableResult
Table.executeInsert(String tablePath, boolean overwrite): TableResult
Table.explain(ExplainDetail... details): String
Table.execute(): TableResult
There are two issues need further discussion, one is whether
`TableEnvironment.executeSql(String statement): TableResult` needs to
support multiline statement (or whether `TableEnvironment` needs to support
multiline statement), and another one is whether `StatementSet.execute()`
needs to throw exception.
please refer to the feedback document [2] for the details.
Any suggestions are warmly welcomed!
[1]
https://wiki.apache.org/confluence/pages/viewpage.action?pageId=134745878
[2]
https://docs.google.com/document/d/1ueLjQWRPdLTFB_TReAyhseAX-1N3j4WYWD0F02Uau0E/edit
Best,
Godfrey
