Nested garbage-collection policy

Create a column family with a nested garbage-collection policy, if supported.

Documentation pages that include this code sample

To view the code sample used in context, see the following documentation:

Code sample

C#

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

// Create a nested GC rule:
// Drop cells that are either older than the 10 recent versions
// OR
// Drop cells that are older than 5 days AND older than the 2 recent versions.
// Initialize request argument(s).
GcRule.Types.Intersection intersectionRule = new GcRule.Types.Intersection
{
    Rules =
    {
        new GcRule { MaxNumVersions = 2 },
        new GcRule { MaxAge = Duration.FromTimeSpan(TimeSpan.FromDays(5)) }
    }
};

GcRule.Types.Union nestedRule = new GcRule.Types.Union
{
    Rules =
    {
        new GcRule { MaxNumVersions = 10 },
        new GcRule { Intersection = intersectionRule }
    }
};

GcRule gcRule = new GcRule { Union = nestedRule };

// Column family to create
ColumnFamily columnFamily = new ColumnFamily { GcRule = gcRule };

TableName tableName = new TableName(projectId, instanceId, tableId);

// Modification to create column family
ModifyColumnFamiliesRequest.Types.Modification modification = new ModifyColumnFamiliesRequest.Types.Modification
{
    Create = columnFamily,
    Id = "cf5"
};

ModifyColumnFamiliesRequest request = new ModifyColumnFamiliesRequest
{
    TableName = tableName,
    Modifications = { modification }
};
try
{
    // Make the request
    Table response = bigtableTableAdminClient.ModifyColumnFamilies(request);
    Console.WriteLine("Created column family");
}
catch (Exception ex)
{
    Console.WriteLine($"Error creating column family {ex.Message}");
}

C++

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::TableAdmin admin, std::string const& table_id,
   std::string const& family_name) {
  StatusOr<google::bigtable::admin::v2::Table> schema =
      admin.ModifyColumnFamilies(
          table_id,
          {cbt::ColumnFamilyModification::Create(
              family_name,
              cbt::GcRule::Union(
                  cbt::GcRule::MaxNumVersions(10),
                  cbt::GcRule::Intersection(
                      cbt::GcRule::MaxNumVersions(1),
                      cbt::GcRule::MaxAge(5 * std::chrono::hours(24)))))});

  if (!schema) throw std::runtime_error(schema.status().message());
  std::cout << "Schema modified to: " << schema->DebugString() << "\n";
}

Go

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

import (
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/bigtable"
)

func createFamilyGCNested(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "my-table-name"

	ctx := context.Background()

	adminClient, err := bigtable.NewAdminClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewAdminClient: %v", err)
	}
	defer adminClient.Close()

	columnFamilyName := "cf5"
	if err := adminClient.CreateColumnFamily(ctx, tableName, columnFamilyName); err != nil {
		return fmt.Errorf("CreateColumnFamily(%s): %v", columnFamilyName, err)
	}

	// Create a nested GC rule:
	// Drop cells that are either older than the 10 recent versions
	// OR
	// Drop cells that are older than a month AND older than the 2 recent versions
	maxAge := time.Hour * 24 * 5
	maxAgePolicy := bigtable.MaxAgePolicy(maxAge)
	policy := bigtable.UnionPolicy(
		bigtable.MaxVersionsPolicy(10),
		bigtable.IntersectionPolicy(
			bigtable.MaxVersionsPolicy(2),
			maxAgePolicy))
	if err := adminClient.SetGCPolicy(ctx, tableName, columnFamilyName, policy); err != nil {
		return fmt.Errorf("SetGCPolicy(%s): %v", policy, err)
	}

	fmt.Fprintf(w, "created column family %s with policy: %v\n", columnFamilyName, policy)
	return nil
}

Java

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

// Creates a nested GC rule:
// Drop cells that are either older than the 10 recent versions
// OR
// Drop cells that are older than a month AND older than the 2 recent versions
VersionRule versionRule1 = GCRULES.maxVersions(10);
VersionRule versionRule2 = GCRULES.maxVersions(2);
DurationRule maxAgeRule = GCRULES.maxAge(30, TimeUnit.DAYS);
IntersectionRule intersectionRule = GCRULES.intersection().rule(maxAgeRule).rule(versionRule2);
UnionRule unionRule = GCRULES.union().rule(intersectionRule).rule(versionRule1);

// Creates column family with given GC rule.
try {
  // ModifyColumnFamiliesRequest can be used both for adding and modifying families, here it is
  // being used to add a family
  ModifyColumnFamiliesRequest columnFamiliesRequest =
      ModifyColumnFamiliesRequest.of(tableId).addFamily(COLUMN_FAMILY_5, unionRule);
  adminClient.modifyFamilies(columnFamiliesRequest);
  System.out.println("Created column family: " + COLUMN_FAMILY_5);
} catch (AlreadyExistsException e) {
  System.err.println(
      "Failed to create column family with rule, already exists: " + e.getMessage());
}

Node.js

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

// Create a nested GC rule:
// Drop cells that are either older than the 10 recent versions
// OR
// Drop cells that are older than a month AND older than the 2 recent versions
const nestedRule = {
  union: true,
  versions: 10,
  rule: {
    versions: 2,
    age: {
      // one month
      seconds: 60 * 60 * 24 * 30,
      nanos: 0,
    },
  },
};

[family] = await table.createFamily('cf5', nestedRule);
console.log(`Created column family ${family.id}`);

PHP

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

use Google\Cloud\Bigtable\Admin\V2\GcRule\Intersection as GcRuleIntersection;
use Google\Cloud\Bigtable\Admin\V2\ModifyColumnFamiliesRequest\Modification;
use Google\Cloud\Bigtable\Admin\V2\GcRule\Union as GcRuleUnion;
use Google\Cloud\Bigtable\Admin\V2\BigtableTableAdminClient;
use Google\Cloud\Bigtable\Admin\V2\ColumnFamily;
use Google\Cloud\Bigtable\Admin\V2\GcRule;
use Google\Protobuf\Duration;

/**
 * Create a new column family with a nested GC rule
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance where the table resides
 * @param string $tableId The ID of the table in which the rule needs to be created
 */
function create_family_gc_nested(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    $tableAdminClient = new BigtableTableAdminClient();

    $tableName = $tableAdminClient->tableName($projectId, $instanceId, $tableId);

    print('Creating column family cf5 with a Nested GC rule...' . PHP_EOL);
    // Create a column family with nested GC policies.
    // Create a nested GC rule:
    // Drop cells that are either older than the 10 recent versions
    // OR
    // Drop cells that are older than a month AND older than the
    // 2 recent versions
    $columnFamily5 = new ColumnFamily();
    $rule1 = (new GcRule())->setMaxNumVersions(10);

    $rule2Intersection = new GcRuleIntersection();
    $rule2Duration1 = new Duration();
    $rule2Duration1->setSeconds(3600 * 24 * 30);
    $rule2Array = [
        (new GcRule())->setMaxAge($rule2Duration1),
        (new GcRule())->setMaxNumVersions(2)
    ];
    $rule2Intersection->setRules($rule2Array);
    $rule2 = new GcRule();
    $rule2->setIntersection($rule2Intersection);

    $nestedRule = new GcRuleUnion();
    $nestedRule->setRules([
        $rule1,
        $rule2
    ]);
    $nestedRule = (new GcRule())->setUnion($nestedRule);

    $columnFamily5->setGCRule($nestedRule);

    $columnModification = new Modification();
    $columnModification->setId('cf5');
    $columnModification->setCreate($columnFamily5);
    $tableAdminClient->modifyColumnFamilies($tableName, [$columnModification]);

    print('Created column family cf5 with a Nested GC rule.' . PHP_EOL);
}

Python

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

    print('Creating column family cf5 with a Nested GC rule...')
    # Create a column family with nested GC policies.
    # Create a nested GC rule:
    # Drop cells that are either older than the 10 recent versions
    # OR
    # Drop cells that are older than a month AND older than the
    # 2 recent versions
    rule1 = column_family.MaxVersionsGCRule(10)
    rule2 = column_family.GCRuleIntersection([
        column_family.MaxAgeGCRule(datetime.timedelta(days=30)),
        column_family.MaxVersionsGCRule(2)])

    nested_rule = column_family.GCRuleUnion([rule1, rule2])

    column_family5 = table.column_family('cf5', nested_rule)
    column_family5.create()
    print('Created column family cf5 with a Nested GC rule.')

Ruby

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

# Create a nested GC rule:
# Drop cells that are either older than the 10 recent versions
# OR
# Drop cells that are older than a month AND older than the 2 recent versions
max_versions_rule1 = Google::Cloud::Bigtable::GcRule.max_versions 10
max_age_rule = Google::Cloud::Bigtable::GcRule.max_age 60 * 60 * 24 * 5
max_versions_rule2 = Google::Cloud::Bigtable::GcRule.max_versions 2
intersection_gc_rule = Google::Cloud::Bigtable::GcRule.intersection max_age_rule, max_versions_rule2
nested_gc_rule = Google::Cloud::Bigtable::GcRule.union max_versions_rule1, intersection_gc_rule

What's next

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