lookup schemas in a case-insensitive way

[drewbanin]

Issue

Issue description

Snowflake information schema queries should be case-insensitive, but the Snowflake plugin does not override the default implementation of list_schemas which is case-sensitive.

We should either change the default implementation of list_schemas to be case-insensitive, or we should override the Snowflake implementation to do a case-insensitive lookup. Let's also scan for other case-sensitive default implementations that aren't overridden by the Snowflake plugin.

Results

Given schema: my_schema in profiles.yml, dbt furnishes the following list_schemas query on Snowflake:

select distinct schema_name
    from dw_dev.information_schema.schemata
    where catalog_name = 'my_schema'

dbt uses this query to determine which schemas already exist, circumventing a create schema if not exists ... query. This issue probably only manifests in an error if the dbt user does not have permissions to create a new schema.

System information

The output of dbt --version:

0.13.0

[beckjake]

Fixed in #1412