java.sql.DatabaseMetaData.getImportedKeys()/getMaxIndexKeys() fails against Amazon Redshift

[garrettpatterson]

When using Mondrian schema workbench, it is unable to list databases in the schema, the error is: org.postgresql.util.PSQLException: "Unable to determine a value for MaxIndexKeys due to missing system catalog data."

It appears to be incompatibility of SQL used to query metadata and the version which Redshift presents itself as:
https://github.com/pgjdbc/pgjdbc/blob/master/org/postgresql/jdbc2/AbstractJdbc2DatabaseMetaData.java#L46-59

The query it tries to run reporting as an 8.0 PostgreSQL:
SELECT * FROM pg_catalog.pg_settings WHERE name='max_index_keys'

Query that actually works (Min version >= 7.3 query):
SELECT t1.typlen/t2.typlen from pg_catalog.pg_namespace n, pg_catalog.pg_type t1, pg_catalog.pg_type t2 WHERE t1.typnamespace=n.oid AND n.nspname='pg_catalog' AND t1.typelem=t2.oid AND t1.typname='oidvector'

Is there a way to determine a Redshift version within the driver? Set something in JDBC configuration for Redshift?

[davecramer]

if it presents as 8.0 and the code checks for min version >= 7.3 then it
should work ?

Dave Cramer

On Mon, Aug 12, 2013 at 6:28 PM, garrettpatterson
notifications@github.comwrote:

When using Mondrian schema workbench, it is unable to list databases in
the schema, the error is: org.postgresql.util.PSQLException: "Unable to
determine a value for MaxIndexKeys due to missing system catalog data."

It appears to be incompatibility of SQL used to query metadata and the
version which Redshift presents itself as:

https://github.com/pgjdbc/pgjdbc/blob/master/org/postgresql/jdbc2/AbstractJdbc2DatabaseMetaData.java#L46-59

The query it tries to run reporting as an 8.0 PostgreSQL:
SELECT * FROM pg_catalog.pg_settings WHERE name='max_index_keys'

Query that actually works (Min version >= 7.3 query):
SELECT t1.typlen/t2.typlen from pg_catalog.pg_namespace n,
pg_catalog.pg_type t1, pg_catalog.pg_type t2 WHERE t1.typnamespace=n.oid
AND n.nspname='pg_catalog' AND t1.typelem=t2.oid AND t1.typname='oidvector'

Is there a way to determine a Redshift version within the driver? Set
something in JDBC configuration for Redshift?

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/79
.

[davecramer]

I think they recommend using only 8.4

[garrettpatterson]

Redshift presents as >8, yet the auto-discovery query for PostGres version 8 and up does not work. The query that does work and matches the metadata schema is that of Postgres version >=7.3 but < version 8. I wouldn't consider "I think they recommend using only 8.4" a decent reason to close this.

[davecramer]

I'll reopen it for now then. I have to find a way to get a hold of redshift. In some ways it's really their bug

[garrettpatterson]

Agreed - they're the ones doing out of band things. thanks for re-opening, would be fine if this went to an enhancement instead since its more about support than a true bug.

[ringerc]

On 04/26/2014 03:57 AM, Dave Cramer wrote:

I'll reopen it for now then. I have to find a way to get a hold of
redshift. In some ways it's really their bug

I have some contacts within Amazon here. I'll get in touch and see if I
can get a contact within the Redshift team. They really need to start
contributing to PgJDBC if they're going to be relying on it - and I'd
really rather they contributed to mainline PgJDBC than suddenly pop up
with a fork.

Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services

[ringerc]

I've had no response from Amazon/ParAccel. They seem to content to ignore issues with Redshift and PgJDBC.

[davecramer]

Well I have an account they will let us use, but I'm less than motivated to
help them. I had to ask them for the account

Dave Cramer

On 26 June 2014 05:21, Craig Ringer notifications@github.com wrote:

I've had no response from Amazon/ParAccel. They seem to content to ignore
issues with Redshift and PgJDBC.

—
Reply to this email directly or view it on GitHub
#79 (comment).

[ringerc]

On 06/26/2014 05:44 PM, Dave Cramer wrote:

Well I have an account they will let us use, but I'm less than motivated to
help them. I had to ask them for the account

... and they still haven't donated one to the SQLFiddle folks, AFAIK.
Which is not sensible.

I see little reason to put any effort into supporting their
closed-source product when they don't dedicate any resources to helping
out here.

Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services

[davecramer]

Not going to fix this