Re: Driver Module

Hi Dave,

We looked through the places where there is existing version checking and
there isn't a ton of it. Our current plan for supporting Greenplum in
pgAdmin4 was not necessarily to support all the features of pgAdmin4, but
to at least get the core functionality working.
I'm not too concerned about there being a ton of switches, because I don't
think most features will need to be disabled. We will also likely make
changes to Greenplum to support certain features like query plans rather
than doing all the changes on the pgAdmin4 side.

What I would like to see though is version checking that happens in one
place and is not tied exclusively to either flavor or version, but to a
combination of the two. E.g. Greenplum 5.0 might support a feature that is
not supported in 8.3 postgres.

Tira & George

On Wed, Jan 11, 2017 at 11:24 PM, Robert Eckhardt <reckhardt(at)pivotal(dot)io>
wrote:

>
>
> On Wed, Jan 11, 2017 at 8:07 PM, Dave Page <dpage(at)pgadmin(dot)org> wrote:
>
>> Hi
>>
>> On Wed, Jan 11, 2017 at 10:24 PM, George Gelashvili
>> <ggelashvili(at)pivotal(dot)io> wrote:
>> > Hi Dave,
>> >
>> > Thanks for the pointer.
>> > We realized that many of the changes we would need to make for
>> supporting
>> > Greenplum would need to go where there is pg version checking
>> throughout the
>> > code. This is because unlike PPAS which mostly adds additional features,
>> > Greenplum is based on postgres 8.3.
>>
>> Isn't Heikki fixing that for your next release?
>>
>
> The current release is 8.2, we aren't trying to make that work with
> pgAdmin4. Heikki did a yeomans work and the next release will be based on
> 8.3. Future releases should be more than one Postgres version at a time but
> there was a lot of cleanup to do before we could start the Postgres
> merging.
>
>
>>
>> > It looks like much of the version checking logic is repeated at points
>> where
>> > the features are differentiated by postgres version.
>> >
>> > It might make sense at this point to refactor the way that feature
>> flagging
>> > is done to be a little bit more unified between server types and
>> postgres
>> > versions so that we could for example have logic along the lines of:
>> >
>> > feature_enablement = FeatureEnablement(postgres_flavor,
>> postgres_version)
>> >
>> > #...
>> >
>> > if(feature_enablement.check_internal_triggers ):
>> > # feature call here
>> >
>> > and then in a feature enablement class, reference the various versions
>> and
>> > flavors of postgres.
>> >
>> > Any thoughts on this?
>>
>> I worry that the list of features would end up being huge - we're not
>> just talking about basic things like whether DDL triggers are
>> supported, but the catalog schema (e.g. procpid vs. pid in
>> pg_stat_activity) and small things like whether a particular GUC can
>> be set on a tablespace.
>>
>> Ultimately, you have to do a version check at some point though
>> (unless you're proposing to do something similar to probing the DOM in
>> a browser at runtime). Doesn't GP's version string contain additional
>> info beyond '8.3'? In pgAdmin 3 we had a EdbMinimumVersion(int major,
>> int minor) function in the connection class that basically did:
>>
>> return isEdb && BackendMinimumVersion(x, y);
>>
>> Something like that could check other elements of the GP version number.
>>
>
> Greenplum is about to start leveraging semantic versioning. The version
> number for the next release will be 5.0.0.
>
>
>>
>> --
>> Dave Page
>> Blog: http://pgsnake.blogspot.com
>> Twitter: @pgsnake
>>
>> EnterpriseDB UK: http://www.enterprisedb.com
>> The Enterprise PostgreSQL Company
>>
>>
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>
>