Re: exchange partition waiting for library cache lock

Hi

Looks like it was hard parsing, session 1186 was the session running the exchange partition and was blocked by session 325 who was running PQ against the table being exchanged

SAMPLE_TIME                 SESSION_ID EVENT                 SQL_ID

--------------------------- ---------- --------------------- -------------
------------ ---------------- ---------------- -------- -------------
----------------
04-SEP-23 07.09.25.426 AM         325                        9rkcnmvu2srm0
SELECT                                         Y        Y             Y
04-SEP-23 07.09.25.426 AM         1186 library cache lock    71vzptnahb00h
ALTER TABLE               325                4 N        N             Y

Tim, I will get the statement later today and share.

Thanks

On Mon, Sep 11, 2023 at 8:57 PM Dominic Brooks <dombrooks_at_hotmail.com> wrote:

> Are these blocking queries just executing or parsing? See the various IN%
> flags in ASH output.
>
> Sent from my iPhone
>
> On 11 Sep 2023, at 19:22, Ls Cheng <exriscer_at_gmail.com> wrote:
>
> 
> Forgot to mention that the queries are all parallel queries
>
> On Mon, Sep 11, 2023 at 8:13 PM Ls Cheng <exriscer_at_gmail.com> wrote:
>
>> Hi
>>
>> Running 19.15.
>>
>> I have some batch processes which run exchange partition commands then
>> run some ETL, sometimes the exchange partition takes minutes instead of
>> seconds and the ALTER is waiting for the library cache lock. From ASH we
>> can see that the blocking sessions are running queries against the
>> partition. I tried to reproduce the issue but in my tests the exchange
>> partition runs successfully and there is no library cache lock while the
>> table is being queried.
>>
>> So I wonder what is exactly causing library cache lock to the ALTER TABLE
>> exchange partition?
>>
>> Thanks
>>
>>
>>

libt.tld_type is 1, lib_t.tld_source_file is '/usr/local/lib/aarch64-linux-gnu/perl/5.30.0/auto/share/dist/Mail-DMARC-opendmarc/effective_tld_names.dat'

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