Migrating data from PostgreSQL to YDB

A Managed Service for YDB cluster can get data from PostgreSQL databases in real time. This data is automatically added to YDB tables with names of source schemas and tables.

To run data delivery:

1. Prepare the source cluster.
2. Prepare and activate the transfer.
3. Test the transfer.

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

Getting startedGetting started

Prepare the data transfer infrastructure:

Prepare the source clusterPrepare the source cluster

1. Connect to the database of the source cluster on behalf of the new user.

2. Add test data to the database. In this example, a simple table with information from car sensors is used.

   Create a table:

   CREATE TABLE public.sensors (
       "device_id" text PRIMARY KEY NOT NULL,
       "datetime" timestamp NOT NULL,
       "latitude" real NOT NULL,
       "longitude" real NOT NULL,
       "altitude" real NOT NULL,
       "speed" real NOT NULL,
       "battery_voltage" real,
       "cabin_temperature" real NOT NULL,
       "fuel_level" real
   );
   

   Populate the table with data:

   INSERT INTO public.sensors VALUES
       ('iv9a94th6rzt********', '2020-06-05 17:27:00', 55.70329032, 37.65472196,  427.5,    0, 23.5, 17, NULL),
       ('rhibbh3y08qm********', '2020-06-06 09:49:54', 55.71294467, 37.66542005, 429.13, 55.5, NULL, 18, 32),
       ('iv9a94th678t********', '2020-06-07 15:00:10', 55.70985913, 37.62141918,  417.0, 15.7, 10.3, 17, NULL);
   

3. Prepare the source cluster for transfer.

Prepare and activate the transferPrepare and activate the transfer

1. Create a target endpoint:

   • Database type: YDB.

   • Endpoint parameters:

     • Connection settings:
       • Database: Select the Managed Service for YDB database from the list.
       • Service account ID: Select or create a service account with the ydb.editor role.

2. Create a source endpoint and transfer:

   Manually

   Terraform

   1. Create an endpoint for the previously created PostgreSQL source with the following settings:

      • Database type: PostgreSQL.
      • Endpoint parameters:
        • Installation type: Managed Service for PostgreSQL cluster.
        • Managed Service for PostgreSQL cluster: Created Managed Service for PostgreSQL cluster.
        • Database: Name of the DB created in the cluster Managed Service for PostgreSQL.
        • User: Name of the user created in the Managed Service for PostgreSQL cluster.
        • Password: User password.
        • Included tables: <DB_name>.sensors.

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

   3. Activate the transfer.

   1. In the data-transfer-mpg-ydb.tf file, specify the values of parameters:

      • target_endpoint_id: ID of the target endpoint.
      • transfer_enabled: For creating a source endpoint and a transfer, the value is 1.

   2. Make sure 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.

      Once created, your transfer will be activated automatically.

Test the transferTest the transfer

1. Wait for the transfer status to change to Replicating.

2. Make sure the data from the source Managed Service for PostgreSQL cluster has been moved to the Managed Service for YDB database:

   Management console

   1. In the management console, select the folder with the DB you need.
   2. In the list of services, select Managed Service for YDB.
   3. Select the database from the list.
   4. Go to the Navigation tab.
   5. Check that the Managed Service for YDB database contains the public_sensors table with the test data.

3. Connect to the Managed Service for PostgreSQL source cluster and add data to the measurements table:

   INSERT INTO public.sensors VALUES
       ('iv7b74th678t********', '2020-06-08 17:45:00', 53.70987913, 36.62549834, 378.0, 20.5, 5.3, 20, NULL);
   

4. Check that the Managed Service for YDB database shows information about the added row:

   Management console

   YDB CLI

   1. In the management console, select the folder with the DB you need.
   2. In the list of services, select Managed Service for YDB.
   3. Select the database from the list.
   4. Go to the Navigation tab.
   5. Check that new data has been added to the public_sensors table.

   1. Connect to the Managed Service for YDB database.

   2. Check that new data has been added to the public_sensors table:

      ydb table query execute \
        --query "SELECT * \
        FROM public_sensors"
      

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: