diff --git a/services/horizon/cmd/db.go b/services/horizon/cmd/db.go
index 2769273493..8f3e2ae9eb 100644
--- a/services/horizon/cmd/db.go
+++ b/services/horizon/cmd/db.go
@@ -27,6 +27,8 @@ import (
 	hlog "github.com/stellar/go/support/log"
 )
 
+var runDBReingestRangeFn = runDBReingestRange
+
 var dbCmd = &cobra.Command{
 	Use:   "db [command]",
 	Short: "commands to manage horizon's postgres db",
@@ -391,6 +393,11 @@ var dbReingestRangeCmd = &cobra.Command{
 			}
 			storageBackendConfig.BufferedStorageBackendFactory = ledgerbackend.NewBufferedStorageBackend
 			storageBackendConfig.DataStoreFactory = datastore.NewDataStore
+			// when using buffered storage, performance observations have noted optimal parallel batch size
+			// of 100, apply that as default if the flag was absent.
+			if !viper.IsSet("parallel-job-size") {
+				parallelJobSize = 100
+			}
 			options.NoCaptiveCore = true
 		}
 
@@ -398,7 +405,7 @@ var dbReingestRangeCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		return runDBReingestRange(
+		return runDBReingestRangeFn(
 			[]history.LedgerRange{{StartSequence: argsUInt32[0], EndSequence: argsUInt32[1]}},
 			reingestForce,
 			parallelWorkers,
@@ -477,7 +484,7 @@ var dbFillGapsCmd = &cobra.Command{
 			hlog.Infof("found gaps %v", gaps)
 		}
 
-		return runDBReingestRange(gaps, reingestForce, parallelWorkers, *globalConfig, storageBackendConfig)
+		return runDBReingestRangeFn(gaps, reingestForce, parallelWorkers, *globalConfig, storageBackendConfig)
 	},
 }
 
diff --git a/services/horizon/cmd/db_test.go b/services/horizon/cmd/db_test.go
new file mode 100644
index 0000000000..3942f8d91a
--- /dev/null
+++ b/services/horizon/cmd/db_test.go
@@ -0,0 +1,98 @@
+package cmd
+
+import (
+	"testing"
+
+	horizon "github.com/stellar/go/services/horizon/internal"
+	"github.com/stellar/go/services/horizon/internal/db2/history"
+	"github.com/stellar/go/services/horizon/internal/ingest"
+	"github.com/stellar/go/support/db/dbtest"
+	"github.com/stretchr/testify/require"
+	"github.com/stretchr/testify/suite"
+)
+
+func TestDBCommandsTestSuite(t *testing.T) {
+	dbCmdSuite := &DBCommandsTestSuite{}
+	suite.Run(t, dbCmdSuite)
+}
+
+type DBCommandsTestSuite struct {
+	suite.Suite
+	dsn string
+}
+
+func (s *DBCommandsTestSuite) SetupSuite() {
+	runDBReingestRangeFn = func([]history.LedgerRange, bool, uint,
+		horizon.Config, ingest.StorageBackendConfig) error {
+		return nil
+	}
+
+	newDB := dbtest.Postgres(s.T())
+	s.dsn = newDB.DSN
+
+	RootCmd.SetArgs([]string{
+		"db", "migrate", "up", "--db-url", s.dsn})
+	require.NoError(s.T(), RootCmd.Execute())
+}
+
+func (s *DBCommandsTestSuite) TestDefaultParallelJobSizeForBufferedBackend() {
+	RootCmd.SetArgs([]string{
+		"db", "reingest", "range",
+		"--db-url", s.dsn,
+		"--network", "testnet",
+		"--parallel-workers", "2",
+		"--ledgerbackend", "datastore",
+		"--datastore-config", "../config.storagebackend.toml",
+		"2",
+		"10"})
+
+	require.NoError(s.T(), dbReingestRangeCmd.Execute())
+	require.Equal(s.T(), parallelJobSize, uint32(100))
+}
+
+func (s *DBCommandsTestSuite) TestDefaultParallelJobSizeForCaptiveBackend() {
+	RootCmd.SetArgs([]string{
+		"db", "reingest", "range",
+		"--db-url", s.dsn,
+		"--network", "testnet",
+		"--stellar-core-binary-path", "/test/core/bin/path",
+		"--parallel-workers", "2",
+		"--ledgerbackend", "captive-core",
+		"2",
+		"10"})
+
+	require.NoError(s.T(), RootCmd.Execute())
+	require.Equal(s.T(), parallelJobSize, uint32(100_000))
+}
+
+func (s *DBCommandsTestSuite) TestUsesParallelJobSizeWhenSetForCaptive() {
+	RootCmd.SetArgs([]string{
+		"db", "reingest", "range",
+		"--db-url", s.dsn,
+		"--network", "testnet",
+		"--stellar-core-binary-path", "/test/core/bin/path",
+		"--parallel-workers", "2",
+		"--parallel-job-size", "5",
+		"--ledgerbackend", "captive-core",
+		"2",
+		"10"})
+
+	require.NoError(s.T(), RootCmd.Execute())
+	require.Equal(s.T(), parallelJobSize, uint32(5))
+}
+
+func (s *DBCommandsTestSuite) TestUsesParallelJobSizeWhenSetForBuffered() {
+	RootCmd.SetArgs([]string{
+		"db", "reingest", "range",
+		"--db-url", s.dsn,
+		"--network", "testnet",
+		"--parallel-workers", "2",
+		"--parallel-job-size", "5",
+		"--ledgerbackend", "datastore",
+		"--datastore-config", "../config.storagebackend.toml",
+		"2",
+		"10"})
+
+	require.NoError(s.T(), RootCmd.Execute())
+	require.Equal(s.T(), parallelJobSize, uint32(5))
+}
diff --git a/services/horizon/internal/integration/parameters_test.go b/services/horizon/internal/integration/parameters_test.go
index f50647abc7..333ed744c6 100644
--- a/services/horizon/internal/integration/parameters_test.go
+++ b/services/horizon/internal/integration/parameters_test.go
@@ -127,8 +127,7 @@ func TestEnvironmentPreserved(t *testing.T) {
 // using NETWORK environment variables, history archive urls or network passphrase
 // parameters are also set.
 func TestInvalidNetworkParameters(t *testing.T) {
-	var captiveCoreConfigErrMsg = integration.HorizonInitErrStr + ": error generating captive " +
-		"core configuration: invalid config: %s parameter not allowed with the %s parameter"
+	var captiveCoreConfigErrMsg = integration.HorizonInitErrStr + ": invalid config: %s parameter not allowed with the %s parameter"
 	testCases := []struct {
 		name         string
 		errMsg       string