How to overcome "DDL statement interfered with this statement"

kfruchtmankfruchtman Vertica Customer

Hi Experts!
I am experiencing many issues with my 10.x vertica.I get a lot of failed queries per day with the reason
"DDL statement interfered with this statement"
what is a good way to deal with this in Vertica?

The backround:
I am pumping data to the db every 5 minutes to a specific table from other databases. so I can imagine that sometimes it is trying to run DDL statements on the same table and this issue is happening.
Is there a way to workaround this problem? e.g - put the queries in some kind of queue in Vertica maybe?

Thanks in advance


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    moshegmosheg Vertica Employee Administrator

    Hello Keren,
    An object acquires an O lock (Owner lock) in some DDL operations, such as DROP_PARTITIONS, TRUNCATE TABLE, and ADD COLUMN. When an object is locked in O mode, it cannot be locked simultaneously by another transaction in any mode.
    For many files or bulk-loads it is advised to use one COPY statement and for trickle feed to use INSERT statements.
    An Insert (I) lock is required to insert data into a table and multiple transactions can lock an object in Insert mode simultaneously, enabling multiple inserts and bulk loads to occur at the same time.

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    kfruchtmankfruchtman Vertica Customer

    Thx for the answer.I am still a bit confused and cannot overcome this issue.
    I am using MERGE statements every5 minutes and getting this error.No other transaction is happening at the same time other than a simple select statement.
    So I am not sure how to debug this issue further.Can I get some more hints?

  • Options
    kfruchtmankfruchtman Vertica Customer

    I am attaching the failed queries log from the vertica mc maybe that can help.
    I think sometimes 2 MERGE statements happen at the same time.should it be the problem?
    file attached.
    Please advise!

  • Options
    kfruchtmankfruchtman Vertica Customer

    Here I attach the vertica.log, maybe it can help understand whey the DDL error occurres?

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