Multiple INSERT INTO within single PyFlink job?

[John Tipper <jo...@hotmail.com>]

Hi all,

Is it possible to have more than one `INSERT INTO ... SELECT ...` statement within a single PyFlink job (on Flink 1.13.6)?

I have a number of output tables that I create and I am trying to write to write to these within a single job, where the example SQL looks like (assume there is an input table called 'input'):

sql1 = "INSERT INTO out1 (col1, col2) SELECT col1, col2 FROM input"
sql2 = "INSERT INTO out2 (col3, col4) SELECT col3, col4 FROM input"

env.execute_sql(sql1)
env.execute_sql(sql2)


When this is run inside a Flink cluster inside Kinesis on AWS, I get a failure: "Cannot have more than one execute() or executeAsync() call in a single environment".  When I look at the Flink web UI, I can see that there is one job called "insert-into_default_catalog.default_database.out1".  Does Flink separate out each INSERT statement into a separate job? It looks like it tries to create one job for the first query and then fails to create a second job for the second query.

Is there any way of getting it to run as a single job using SQL, without having to move away from SQL and the Table API?

Many thanks,

John

Re: Multiple INSERT INTO within single PyFlink job?

[John Tipper <jo...@hotmail.com>]

Ah, found it: I need to use add_insert_sql()​ in order to use multiple insert statements:

https://nightlies.apache.org/flink/flink-docs-release-1.14/docs/dev/table/sql/insert/#insert-statement

https://aws.amazon.com/blogs/big-data/build-a-real-time-streaming-application-using-apache-flink-python-api-with-amazon-kinesis-data-analytics/


Sorry for the noise.
________________________________
From: John Tipper <jo...@hotmail.com>
Sent: 29 April 2022 14:07
To: user@flink.apache.org <us...@flink.apache.org>
Subject: Multiple INSERT INTO within single PyFlink job?

Hi all,

Is it possible to have more than one `INSERT INTO ... SELECT ...` statement within a single PyFlink job (on Flink 1.13.6)?

I have a number of output tables that I create and I am trying to write to write to these within a single job, where the example SQL looks like (assume there is an input table called 'input'):

sql1 = "INSERT INTO out1 (col1, col2) SELECT col1, col2 FROM input"
sql2 = "INSERT INTO out2 (col3, col4) SELECT col3, col4 FROM input"

env.execute_sql(sql1)
env.execute_sql(sql2)


When this is run inside a Flink cluster inside Kinesis on AWS, I get a failure: "Cannot have more than one execute() or executeAsync() call in a single environment".  When I look at the Flink web UI, I can see that there is one job called "insert-into_default_catalog.default_database.out1".  Does Flink separate out each INSERT statement into a separate job? It looks like it tries to create one job for the first query and then fails to create a second job for the second query.

Is there any way of getting it to run as a single job using SQL, without having to move away from SQL and the Table API?

Many thanks,

John