markporoshin / dbt-greenplum

Adaptation postgres adapter for Greenplum
36 stars 22 forks source link

dbt logo

Unit Tests Badge Integration Tests Badge

dbt enables data analysts and engineers to transform their data using the same practices that software engineers use to build applications.

dbt is the T in ELT. Organize, cleanse, denormalize, filter, rename, and pre-aggregate the raw data in your warehouse so that it's ready for analysis.

dbt-greenplum

The dbt-greenplum package contains the code enabling dbt to work with Greenplum. This adapter based on postgres-adapter with a bit difference for a greenplum specific features

Installation

Easiest way to start use dbt-greenplum is to install it using pip pip install dbt-greenplum==<version>

Where <version> is same as your dbt version

Available versions:

Supported Features

You can specify following settings:

Heap table example

To create heap table set appendoptimized parameter value to false

{{
   config(
      ...
      materialized='table',
      appendoptimized=false
      ...
   )
}}

select 1 as "id"

will produce following SQL code

create  table "<db_name>"."<schema_name>"."<table_name>"
with (
   appendoptimized=false
) as (
   select 1 as "id"
)
DISTRIBUTED RANDOMLY;

Appendoptimized table example

You can use appendopimized or appendonly(legacy) to create appendoptimized table

Such model definition

{{
    config(
        materialized='table',
        distributed_by='id',
        appendoptimized=true,
        orientation='column',
        compresstype='ZLIB',
        compresslevel=1,
        blocksize=32768
    )
}}

with source_data as (

    select 1 as id
    union all
    select null as id

)

select *
from source_data

will produce following sql code

create  table "dvault"."dv"."my_first_dbt_model__dbt_tmp"
with (
    appendoptimized=true,
    blocksize=32768,
    orientation=column,
    compresstype=ZLIB,
    compresslevel=1
)
as (
  with source_data as (
      select 1 as id
      union all
      select null as id
    )
  select *
  from source_data
)  
distributed by (id);

alter table "dvault"."dv"."my_first_dbt_model__dbt_tmp" rename to "my_first_dbt_model";

Partitions

Greenplum does not support partitions with create table as construction, so you need to build model in two steps

To implement partitions into you dbt-model you need to specify on of the following config parameters:

Let consider examples of definition model with partitions

Table partition hints

Too check generate sql script use -d option: dbt -d run <...> -m <models>

If you want implement complex partition logic with subpartition or something else use raw_partition parameter

Truncate+insert incremental strategy

You can use this incremental strategy to safely reload models without cascade dropping dependent objects due to Greenplum's transactional TRUNCATE operation realization

Model definition example:

{{
   config(
      ...
      materialized='incremental',
      incremental_strategy='truncate+insert',
      ...
   )
}}

select *
from source_data

Getting started

Join the dbt Community

Reporting bugs and contributing code

Code of Conduct

Everyone interacting in the dbt project's codebases, issue trackers, chat rooms, and mailing lists is expected to follow the dbt Code of Conduct.