Liquibase extension to add Snowflake support
Initial release supports applying formatted sql changesets. It might support other types of refactorings but they haven't been tested. Some of the interesting overrides / extensions are documented below.
Snowflake's current_timestamp function returns a timestamp_ltz datetype, while
the datetime Liquibase datatype maps to a Snowflake timestamp_ntz column. To avoid exceptions, the current_timestamp
is cast to a timestamp_ntz. Without the cast, exceptions of the form given below occur.
SQL compilation error: Expression type does not match column data type, expecting TIMESTAMP_NTZ(9) but got TIMESTAMP_LTZ(9)
The Snowflake JDBC drivers implementation of DatabaseMetadata.getTables() hard codes quotes around the catalog, schema and
table names, resulting in queries of the form:
show tables like 'DATABASECHANGELOG' in schema "sample_db"."sample_schema"
This results in the DATABASECHANGELOG table not being found, even after it has been created. Since Snowflake stores
catalog and schema names in upper case, the getJdbcCatalogName returns an upper case value.
The datetime datatype in Snowflake is an alias for the datatype timestamp_ntz, Date and Time Data Types.
The TimestampNTZType class clarifies this mapping from Liquibase datetime to Snowflake timestamp_ntz.