Re: ATTACH/DETACH partitions and locking

On 2019-Jun-13, Pavel Luzanov wrote:

> Hello,
> 
> According to patch[1] and after playing with v12 beta1 I think that this
> item can be dropped from "5.11.3. Implementation Using Inheritance" section
> of v12 docs:
> 
> "Some operations require a stronger lock when using declarative partitioning
> than when using table inheritance. For example, adding or removing a
> partition to or from a partitioned table requires taking an ACCESS EXCLUSIVE
> lock on the parent table, whereas a SHARE UPDATE EXCLUSIVE lock is enough in
> the case of regular inheritance."

Hmm ... while you're correct that ALTER TABLE ATTACH PARTITION no longer
uses AccessExclusive lock, ALTER TABLE DETACH PARTITION continues to.
So we could remove the "adding to" bit of the paragraph, but not remove
it completely.

https://www.postgresql.org/message-id/CA%2BTgmoY13KQZF-%3DHNTrt9UYWYx3_oYOQpu9ioNT49jGgiDpUEA%40mail.gmail.com

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Álvaro Herrera                https://www.2ndQuadrant.com/
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