Loading data from Object Storage to a Greenplum® data mart

You can migrate data from Object Storage to the Managed Service for Greenplum® table using Data Transfer. To do this:

1. Prepare the test data.
2. Create a database in the target cluster.
3. Prepare and activate the transfer.
4. Test the transfer.

If you no longer need the resources you created, delete them.

Getting startedGetting started

1. Prepare the infrastructure:

   Manually

   Using Terraform

   1. Create a Managed Service for Greenplum® target cluster in any applicable configuration with publicly available hosts and the following settings:

      • Username: user1
      • Password: <user_password>

   2. If using security groups in your cluster, make sure they are configured correctly and allow connecting to the cluster.

   3. Create an Object Storage bucket.

   4. Create a service account named storage-viewer with the storage.viewer role. The transfer will use it to access the bucket.

   5. Create a static access key for the storage-viewer service account.

   1. If you do not have Terraform yet, install it.

   2. Get the authentication credentials. You can add them to environment variables or specify them later in the provider configuration file.

   3. Configure and initialize a provider. There is no need to create a provider configuration file manually, you can download it.

   4. Place the configuration file in a separate working directory and specify the parameter values. If you did not add the authentication credentials to environment variables, specify them in the configuration file.

   5. Download the object-storage-to-greenplum.tf configuration file to the same working directory.

      This file describes:

      • Network.
      • Subnet.
      • Security group required to connect to a cluster.
      • Service account to be used to create and access the bucket.
      • Yandex Lockbox secret which will store the static key of the service account to configure the source endpoint.
      • Object Storage source bucket.
      • Managed Service for Greenplum® target cluster.
      • Transfer.

   6. In the object-storage-to-greenplum.tf file, specify the values of the following variables:

      • folder_id: Cloud folder ID, same as in the provider settings.
      • bucket_name: Bucket name consistent with the naming conventions.
      • gp_version: Greenplum® version.
      • gp_password: Greenplum® user password.

   7. Check that the Terraform configuration files are correct using this command:

      terraform validate
      

      If there are any errors in the configuration files, Terraform will point them out.

   8. Create the required infrastructure:

      1. Run the command to view planned changes:

         terraform plan
         

         If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.

      2. If you are happy with the planned changes, apply them:

         1. Run the command:

            terraform apply
            

         2. Confirm the update of resources.

         3. Wait for the operation to complete.

      All the required resources will be created in the specified folder. You can check resource availability and their settings in the management console.

2. Enable the Access from Data Transfer option in the target cluster.

Prepare the test dataPrepare the test data

1. Prepare two CSV files with test data:

   • demo_data1.csv:

     1,Anna
     2,Robert
     3,Umar
     4,Algul
     5,Viktor
     

   • demo_data2.csv:

     6,Maria
     7,Alex
     

2. Upload the demo_data1.csv file to the Object Storage bucket.

Create a database in the target clusterCreate a database in the target cluster

1. Connect to the auxiliary postgres database in the Managed Service for Greenplum® target cluster as user1.

2. Create a database named db1:

   CREATE DATABASE db1;
   

Prepare and activate the transferPrepare and activate the transfer

1. Create a source endpoint of the Object Storage type with the following settings:

   • Database type: Object Storage

   • Bucket: Bucket name in Object Storage

   • Access Key ID: Public part of the service account static key. If you created your infrastructure with Terraform, copy the key value from the Yandex Lockbox secret.

   • Secret Access Key: Private part of the service account static key. If you created your infrastructure with Terraform, copy the key value from the Yandex Lockbox secret.

   • Endpoint: https://storage.yandexcloud.net

   • Region: ru-central1

   • Data format: CSV

   • Delimiter: Comma (,)

   • Table: table1

   • Result table schema: Select Manual and specify field names and data types:

     • Id: Int64
     • Name: UTF8

   Leave the default values for other properties.

2. Create a target endpoint of the Greenplum® type and specify the cluster connection parameters in it:

   • Connection type: Managed Service for Greenplum cluster
   • Managed Service for Greenplum cluster: <Greenplum®_target_cluster_name> from the drop-down list
   • Database: db1
   • User: user1
   • Password: <user_password>

3. Create and activate the transfer:

   Manually

   Using Terraform

   1. Create a transfer of the Snapshot and replication type that will use the created endpoints.

   2. Activate the transfer and wait for its status to change to Replicating.

   1. In the object-storage-to-greenplum.tf file, specify these variables:

      • source_endpoint_id: Source endpoint ID.
      • target_endpoint_id: Target endpoint ID.
      • transfer_enabled: 1 to create a transfer.

   2. Check that the Terraform configuration files are correct using this command:

      terraform validate
      

      If there are any errors in the configuration files, Terraform will point them out.

   3. Create the required infrastructure:

      1. Run the command to view planned changes:

         terraform plan
         

         If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.

      2. If you are happy with the planned changes, apply them:

         1. Run the command:

            terraform apply
            

         2. Confirm the update of resources.

         3. Wait for the operation to complete.

   4. The transfer will be activated automatically. Wait for its status to change to Replicating.

Test the transferTest the transfer

Check the transfer performance by testing the copy and replication processes.

Test the copy processTest the copy process

1. Connect to db1 in the Managed Service for Greenplum® target cluster.

2. Run the following query:

   SELECT * FROM public.table1;
   

   Response example

     __file_name  | __row_index | Id |  Name
   ---------------+-------------+----+--------
   demo_data1.csv |           1 |  1 | Anna
   demo_data1.csv |           2 |  2 | Robert
   demo_data1.csv |           3 |  3 | Umar
   demo_data1.csv |           4 |  4 | Algul
   demo_data1.csv |           5 |  5 | Viktor
   

Test the replication processTest the replication process

1. Upload the demo_data2.csv file to the Object Storage bucket.

2. Make sure the data from demo_data2.csv has been added to the target database:

   1. Connect to db1 in the Managed Service for Greenplum® target cluster.

   2. Run the following query:

      SELECT * FROM public.table1;
      

      Response example

        __file_name  | __row_index | Id |  Name
      ---------------+-------------+----+--------
      demo_data1.csv |           1 |  1 | Anna
      demo_data1.csv |           2 |  2 | Robert
      demo_data1.csv |           3 |  3 | Umar
      demo_data1.csv |           4 |  4 | Algul
      demo_data1.csv |           5 |  5 | Viktor
      demo_data2.csv |           1 |  6 | Maria
      demo_data2.csv |           2 |  7 | Alex
      

Delete the resources you createdDelete the resources you created

Some resources are not free of charge. To avoid paying for them, delete the resources you no longer need:

• Transfer.

• Source endpoint.

• Target endpoint.

• Delete the other resources depending on how they were created:

  Manually

  Using Terraform

  • Managed Service for Greenplum® cluster.
  • Object Storage bucket.

  1. Delete all objects from the bucket.

  2. In the terminal window, go to the directory containing the infrastructure plan.

  3. Delete the object-storage-to-greenplum.tf configuration file.

  4. Check that the Terraform configuration files are correct using this command:

     terraform validate
     

     If there are any errors in the configuration files, Terraform will point them out.

  5. Confirm updating the resources.

     1. Run the command to view planned changes:

        terraform plan
        

        If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.

     2. If you are happy with the planned changes, apply them:

        1. Run the command:

           terraform apply
           

        2. Confirm the update of resources.

        3. Wait for the operation to complete.

     All the resources described in the object-storage-to-greenplum.tf configuration file will be deleted.