Re: transferring data between Postgres databases

On 25/10/2016 7:09 AM, Erik Cederstrand wrote:
>> Den 24. okt. 2016 kl. 06.04 skrev Mike Dewhirst<miked@dewhirst.com.au>:
>>
>> I have a user who has done a lot of work (instead of playing) in the staging server and now wants to get that work into the production database.
>>
>> I'm about to research selective dump and load capabilities of Postgres but in the meantime can anyone suggest any shortcuts?
> How much data are we talking about? Is it too much for django-admin dumpdata/loaddata to handle?
>
> Erik
>

Erik and others who have replied; thank you.

I have slept on the problem and decided I have to do the work to turn
the requirement into a data-transfer feature.

The data is not voluminous but is somewhat complex. Companies have
divisions. Divisions have substances. Substances have complex properties
gathered into many different related tables. Some are 1:1, some are 1:m
and then it gets tricky.

Substances have one current safety data sheet (SDS) and one under
user-developemt to be ready in due course to become the new current SDS.
SDSs have releationships with each other as they are legal documents and
need to persist indefinitely in a daisy-chain going back in time to the
big bang. The idea is that workplace safety depends on information on
substances. Lawyers earn money by blaming as many people as possible if
their client has a valid claim for injury. SDSs change as the science
changes or the regulations change or measuring technology changes or
knowledge improves. They must be reviewed every few years anyway even if
nothing has changed.

Each SDS has many sds_hazard records each of which has a relationship
with one reference hazard. It also has many precaution records and many
pictogram (png or jpg hazard symbol) records. Then there are phrases,
reference URLs for academic papers and so it goes.

I forgot to mention that a mixture has its own properties and SDS chain.
A mixture is a substance too. In fact it is a substance with ingredients
which are other substances. Mixture properties are calculated from
ingredient properties and/or entered by users.

Might be talking myself out of my overnight decision.

Thanks for listening.

Mike


The above summary will end up in a ticket for the data-transfer feature.
I can see it is going to be more complex than the users will ever
understand. Having built their

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.
To post to this group, send email to django-users@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/88f59b39-2061-e331-fb22-5eac5d1960e5%40dewhirst.com.au.
For more options, visit https://groups.google.com/d/optout.