Re: pg_upgrade and schema complexity...

On 6/2/23 21:22, Adrian Klaver wrote:
> On 6/2/23 18:06, Ron wrote:
>> On 6/2/23 19:58, Adrian Klaver wrote:
>>> On 6/2/23 17:44, Ron wrote:
>>>> Ran into this when upgrading from 13.11 to 15.3...
>>>>
>>>> The pg_restore phase failed with "ERROR: out of shared memory", and 
>>>> recommended that I increase max_locks_per_transaction. Doing so let the 
>>>> process run to completion.
>>>>
>>>> It took 12.5 minutes to upgrade a 13GB instance.  Soon after, I 
>>>> upgraded a 78GB cluster, and it only took 3.1 minutes.
>>>
>>> Where/how did you measure  those sizes?
>>
>> Does it really matter?
>>
>> START_SECS=$(date +"%s")
>> pg_upgrade ...
>> FINISH_SECS=$(date +"%s")
>> ET=`echo "scale=2;(${FINISH_SECS} - ${START_SECS})/60" | bc`
>> date +"%F %T pg_upgrade finished.  Elapsed time: ${ET} minutes."
>
> Unless I'm not mistaken the above is how the elapsed time was measured. I 
> was looking for the procedure for determining the size.

du -cm -d1 $DATA13
du -cm -d1 $DATA15

>
>>
>> (Text copied between air-gapped computers, so there might be errors.)
>>
>>>>
>>>> (Both are VMs (same number of CPUs and RAM) connected to the same SAN.)
>>>>
>>>> A "pg_dump --schema-only" of the two systems shows that the 
>>>> small-but-slow schema is 5.9M lines.
>>>
>>> Anything special you are doing in this cluster to create all those lines?
>>
>> I do nothing; the schema is provided by the vendor.
>
> Alright so it is not your design, but you do have an idea of what is in 
> the database correct?

"In" like the /purpose/ of the database?  Sure.
"In" like the /design/ of the database?  No; that's all on the vendor.

>
>
>>
>>>
>>> What is the line count for the other instance?
>>
>> 227K rows.
>

-- 
Born in Arizona, moved to Babylonia.