Loading data from Object Storage to a Greenplum® data mart

You can migrate data from Object Storage to the Greenplum® table in Yandex MPP Analytics for PostgreSQL using Data Transfer. Proceed as follows:

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

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

Required paid resourcesRequired paid resources

• Object Storage bucket: Use of storage, data operations (see Object Storage pricing).
• Yandex MPP Analytics for PostgreSQL cluster: Computing resources allocated to hosts, storage and backup size (see Yandex MPP Analytics for PostgreSQL pricing).
• Public IP addresses if public access is enabled for cluster hosts (see Virtual Private Cloud pricing).

Getting startedGetting started

1. Set up the infrastructure:

   Manually

   Using Terraform

   1. Create a Greenplum® target cluster of any suitable configuration with publicly available hosts and the following settings:

      • Username: user1.
      • Password: <user_password>.

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

   3. Create an Object Storage bucket.

   4. Create a service account 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.
      • Cluster access security group.
      • Service account for bucket operations, e.g., creation and access.
      • Yandex Lockbox secret for the service account static key required to configure the source endpoint.
      • Source Object Storage bucket.
      • Greenplum® target cluster in Yandex MPP Analytics for PostgreSQL.
      • 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® password.

   7. Validate your Terraform configuration files using this command:

      terraform validate
      

      Terraform will display any configuration errors detected in your files.

   8. Create the required infrastructure:

      1. Run this command to view the planned changes:

         terraform plan
         

         If you described the configuration correctly, the terminal will display a list of the resources to update and their parameters. This is a verification step that does not apply changes to your resources.

      2. If everything looks correct, apply the changes:

         1. Run this command:

            terraform apply
            

         2. Confirm updating the 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 Greenplum® target cluster as user1.

2. Create a database named db1:

   CREATE DATABASE db1;
   

Prepare and activate your transferPrepare and activate your transfer

1. Create an Object Storage-type source endpoint with the following settings:

   • Database type: Object Storage.

   • Bucket: Object Storage bucket name.

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

   • Secret Access Key: Private part of the service account’s static key. If you created your infrastructure using 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 the following field names and data types:

     • Id: Int64
     • Name: UTF8

   Leave the default values for the other properties.

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

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

3. Create and activate your transfer:

   Manually

   Using Terraform

   1. Create a Snapshot and replication-type transfer configured to use the new 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. Validate your Terraform configuration files using this command:

      terraform validate
      

      Terraform will display any configuration errors detected in your files.

   3. Create the required infrastructure:

      1. Run this command to view the planned changes:

         terraform plan
         

         If you described the configuration correctly, the terminal will display a list of the resources to update and their parameters. This is a verification step that does not apply changes to your resources.

      2. If everything looks correct, apply the changes:

         1. Run this command:

            terraform apply
            

         2. Confirm updating the resources.

         3. Wait for the operation to complete.

   4. The transfer will activate automatically upon creation. Wait for its status to change to Replicating.

Test your transferTest your transfer

Make sure the transfer works correctly by testing copying and replication.

Test copyingTest copying

1. Connect to the db1 database in the Greenplum® target cluster.

2. Run this 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 replicationTest replication

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

2. Verify that the data from demo_data2.csv has been loaded into the target database:

   1. Connect to the db1 database in the Greenplum® target cluster.

   2. Run this 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

To reduce the consumption of resources you do not need, delete them:

1. Delete the transfer.

2. Delete the source endpoint.

3. Delete the target endpoint.

4. Delete the objects from the bucket.

5. Delete other resources using the same method used for their creation:

   Manually

   Using Terraform

   1. Delete the Greenplum® cluster.
   2. Delete the Object Storage bucket.

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

      Warning

      Make sure the directory has no Terraform manifests with the resources you want to keep. Terraform deletes all resources that were created using the manifests in the current directory.

   2. Delete resources:

      1. Run this command:

         terraform destroy
         

      2. Confirm deleting the resources and wait for the operation to complete.

      All the resources described in the Terraform manifests will be deleted.