CODEWITHSUNDEEP
sqlamazon-web-servicestransactionsamazon-redshiftamazon-data-pipeline
Kiril Scherbach
Kiril Scherbach

Reputation: 75

Can AWS Redshift drop a table that is wrapped in transaction?

During the ETL we do the following operations:

    begin transaction;

    drop table if exists target_tmp;
    create table target_tmp like target;

    insert into target_tmp select * from source_a inner join source_b on ...;
    analyze table target_tmp;

    drop table target;
    alter table target_tmp rename to target;

    commit;

The SQL command is performed by AWS Data Pipeline, if this is important.

However, the pipelines sometimes fail with the following error:

    ERROR: table 111566 dropped by concurrent transaction

Redshift supports serializable isolation. Does one of the commands break isolation?

Upvotes: 6

Views: 4020

Answers (1)

systemjack
systemjack

Reputation: 3005

Yes that works, but if generating the temp table takes a while you can expect to see that error for other queries while it runs. You could try generating the temp table in a separate transaction (transaction may not be needed unless you worry about updates to the source tables). Then do a quick rotation of the table names so there is much less time for contention:

-- generate target_tmp first then
begin;
alter table target rename to target_old;
alter table target_tmp rename to target;
commit;
drop table target_old;

Upvotes: 4

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