refactor: adjust configuration parameters for extractors and transformers; optimize batch processing settings

cmd/go_migrate/main.go

@@ -86,7 +86,7 @@ func main() {
 	log.Infof("Migración terminada. Tablas: %d, Errores: %d, Filas totales: %d", len(results), totalErrors, totalProcessed)
 
 	totalDuration := time.Since(startTime)
-	log.Infof("=== Migration completed successfully! ===")
+	// log.Infof("=== Migration completed successfully! ===")
 	log.Infof("Total migration time: %v", totalDuration)
 }
 

cmd/go_migrate/process.go

@@ -57,8 +57,6 @@ func processMigrationJob(
 		StartTime: time.Now(),
 	}
 
-	var rowsRead, rowsLoaded, rowsFailed int64
-
 	var wgQueryColumnTypes errgroup.Group
 	var sourceColTypes, targetColTypes []models.ColumnType
 
@@ -114,16 +112,13 @@ func processMigrationJob(
 	}
 
 	chJobErrors := make(chan custom_errors.JobError, jobErrorsChannelSize)
-	chLoadersErrors := make(chan custom_errors.LoaderError, job.ExtractorQueueSize)
+	chPartitions := make(chan models.Partition)
-	chPartitions := make(chan models.Partition, job.ExtractorQueueSize)
 	chBatchesRaw := make(chan models.Batch, job.ExtractorQueueSize)
 	chBatchesTransformed := make(chan models.Batch, job.TransformerQueueSize)
 
-	var wgActivePartitions sync.WaitGroup
+	var wgActivePartitions, wgActiveBatches, wgExtractors, wgTransformers, wgLoaders sync.WaitGroup
-	var wgActiveBatches sync.WaitGroup
+	var rowsRead, rowsLoaded, rowsFailed int64
-	var wgExtractors sync.WaitGroup
+	var failedPartitionsCount, failedBatchesLoadCount int32
-	var wgTransformers sync.WaitGroup
-	var wgLoaders sync.WaitGroup
 
 	go func() {
 		if err := custom_errors.JobErrorHandler(localCtx, chJobErrors); err != nil {
@@ -133,18 +128,8 @@ func processMigrationJob(
 		}
 	}()
 
-	go custom_errors.LoaderErrorHandler(
-		localCtx,
-		job.Retry,
-		job.MaxExtractorBatchErrors,
-		chLoadersErrors,
-		chBatchesTransformed,
-		chJobErrors,
-		&wgActiveBatches,
-	)
-
 	maxExtractors := min(job.MaxExtractors, len(partitions))
-	log.Infof("Starting %d extractor(s)...", maxExtractors)
+	log.Infof("Starting %d extractor(s)... (%v)", maxExtractors, job.Name)
 
 	for range maxExtractors {
 		wgExtractors.Go(func() {
@@ -159,6 +144,7 @@ func processMigrationJob(
 				chJobErrors,
 				&wgActivePartitions,
 				&rowsRead,
+				&failedPartitionsCount,
 				job.SourceTable.FromJsonColumns,
 			)
 		})
@@ -171,13 +157,15 @@ func processMigrationJob(
 		}
 	}()
 
-	log.Infof("Starting %d transformer(s)...", maxExtractors)
+	log.Infof("Starting %d transformer(s)... (%v)", maxExtractors, job.Name)
 
 	for range maxExtractors {
 		wgTransformers.Go(func() {
-			transformer.Exec(
+			transformer.Consume(
 				localCtx,
 				sourceColTypes,
+				job.Retry,
+				job.TransformerBatchSize,
 				chBatchesRaw,
 				chBatchesTransformed,
 				chJobErrors,
@@ -186,7 +174,7 @@ func processMigrationJob(
 		})
 	}
 
-	log.Infof("Starting %d loader(s)...", job.MaxLoaders)
+	log.Infof("Starting %d loader(s)... (%v)", job.MaxLoaders, job.Name)
 
 	for range job.MaxLoaders {
 		wgLoaders.Go(func() {
@@ -195,39 +183,39 @@ func processMigrationJob(
 				job.TargetTable,
 				targetColTypes,
 				job.Retry,
+				job.LoaderBatchSize,
 				chBatchesTransformed,
 				chJobErrors,
 				&wgActiveBatches,
 				&rowsLoaded,
+				&failedBatchesLoadCount,
 			)
 		})
 	}
 
 	go func() {
-		log.Debugf("Waiting for goroutines (%v)", job.Name)
+		// log.Debugf("Waiting for goroutines (%v)", job.Name)
 
 		wgActivePartitions.Wait()
-		log.Debugf("wgActivePartitions is empty (%v)", job.Name)
+		// log.Debugf("wgActivePartitions is empty (%v)", job.Name)
 		close(chPartitions)
-		log.Debugf("chPartitions is closed (%v)", job.Name)
+		// log.Debugf("chPartitions is closed (%v)", job.Name)
 
 		wgExtractors.Wait()
-		log.Debugf("wgExtractors is empty (%v)", job.Name)
+		// log.Debugf("wgExtractors is empty (%v)", job.Name)
 		close(chBatchesRaw)
-		log.Debugf("chBatchesRaw is closed (%v)", job.Name)
+		// log.Debugf("chBatchesRaw is closed (%v)", job.Name)
 
 		wgTransformers.Wait()
-		log.Debugf("wgTransformers is empty (%v)", job.Name)
+		// log.Debugf("wgTransformers is empty (%v)", job.Name)
+		close(chBatchesTransformed)
+		// log.Debugf("chBatchesTransformed is closed (%v)", job.Name)
 
 		wgActiveBatches.Wait()
-		log.Debugf("wgActiveBatches is empty (%v)", job.Name)
+		// log.Debugf("wgActiveBatches is empty (%v)", job.Name)
-		close(chBatchesTransformed)
-		log.Debugf("chBatchesTransformed is empty (%v)", job.Name)
-		close(chLoadersErrors)
-		log.Debugf("chLoadersErrors is empty (%v)", job.Name)
 
 		wgLoaders.Wait()
-		log.Debugf("wgLoaders is empty (%v)", job.Name)
+		// log.Debugf("wgLoaders is empty (%v)", job.Name)
 
 		cancel()
 	}()
@@ -239,9 +227,9 @@ func processMigrationJob(
 		}
 	}
 
-	log.Debugf("waiting for local context to be done (%v)", job.Name)
+	// log.Debugf("waiting for local context to be done (%v)", job.Name)
 	<-localCtx.Done()
-	log.Debugf("local context done (%v)", job.Name)
+	// log.Debugf("local context done (%v)", job.Name)
 
 	if ctx.Err() != nil {
 		result.Error = ctx.Err()
@@ -256,5 +244,9 @@ func processMigrationJob(
 		result.Error = fmt.Errorf("Row count mismatch: extracted %d rows but loaded %d rows (failed: %d)", result.RowsRead, result.RowsLoaded, result.RowsFailed)
 	}
 
+	if result.RowsRead == 0 {
+		log.Warnf("No rows extracted from (%v)", job.Name)
+	}
+
 	return result
 }

config.yaml

@@ -3,24 +3,24 @@ source_db_type: sqlserver
 target_db_type: postgres
 
 defaults:
-  batches_per_partition: 8
+  batches_per_partition: 4
   max_extractors: 2
-  extractor_batch_size: 25000
+  extractor_batch_size: 5000
   extractor_queue_size: 8
   max_transformers: 2
-  transformer_batch_size: 25000
+  transformer_batch_size: 12500
   transformer_queue_size: 8
   max_loaders: 4
   loader_batch_size: 25000
   truncate_target: true
   truncate_method: TRUNCATE # TRUNCATE | DELETE
-  max_partition_errrors: 5
-  max_extractor_batch_errors: 5
   retry:
     attempts: 3
     base_delay_ms: 500
     max_delay_ms: 10000
     max_jitter_ms: 500
+    max_failed_partitions: 5
+    max_failed_batches_load: 5
 
 jobs:
   - name: cartografia_manzana
@@ -70,10 +70,15 @@ jobs:
         - source: DATA
           target: FILE_URL
           mode: REFERENCE_ONLY
-    max_extractors: 8
+    batches_per_partition: 20
+    max_extractors: 32
+    extractor_batch_size: 1
+    extractor_queue_size: 100
+    max_transformers: 48
+    transformer_batch_size: 500
+    transformer_queue_size: 8
     max_loaders: 4
-    queue_size: 32
+    loader_batch_size: 500
-    batch_size: 1
     retry:
       attempts: 5
       base_delay_ms: 1000

internal/app/config/migration.go

@@ -8,10 +8,12 @@ import (
 )
 
 type RetryConfig struct {
-	Attempts    int `yaml:"attempts"`
+	Attempts             int `yaml:"attempts"`
-	BaseDelayMs int `yaml:"base_delay_ms"`
+	BaseDelayMs          int `yaml:"base_delay_ms"`
-	MaxDelayMs  int `yaml:"max_delay_ms"`
+	MaxDelayMs           int `yaml:"max_delay_ms"`
-	MaxJitterMs int `yaml:"max_jitter_ms"`
+	MaxJitterMs          int `yaml:"max_jitter_ms"`
+	MaxFailedPartitions  int `yaml:"max_failed_partitions"`
+	MaxFailedBatchesLoad int `yaml:"max_failed_batches_load"`
 }
 
 type ToStorageColumnConfig struct {
@@ -25,22 +27,20 @@ type ToStorageConfig struct {
 }
 
 type JobConfig struct {
-	BatchesPerPartition     int         `yaml:"batches_per_partition"`
+	BatchesPerPartition  int         `yaml:"batches_per_partition"`
-	MaxExtractors           int         `yaml:"max_extractors"`
+	MaxExtractors        int         `yaml:"max_extractors"`
-	ExtractorBatchSize      int         `yaml:"extractor_batch_size"`
+	ExtractorBatchSize   int         `yaml:"extractor_batch_size"`
-	ExtractorQueueSize      int         `yaml:"extractor_queue_size"`
+	ExtractorQueueSize   int         `yaml:"extractor_queue_size"`
-	MaxTransformers         int         `yaml:"max_transformers"`
+	MaxTransformers      int         `yaml:"max_transformers"`
-	TransformerBatchSize    int         `yaml:"transformer_batch_size"`
+	TransformerBatchSize int         `yaml:"transformer_batch_size"`
-	TransformerQueueSize    int         `yaml:"transformer_queue_size"`
+	TransformerQueueSize int         `yaml:"transformer_queue_size"`
-	MaxLoaders              int         `yaml:"max_loaders"`
+	MaxLoaders           int         `yaml:"max_loaders"`
-	LoaderBatchSize         int         `yaml:"loader_batch_size"`
+	LoaderBatchSize      int         `yaml:"loader_batch_size"`
-	TruncateTarget          bool        `yaml:"truncate_target"`
+	TruncateTarget       bool        `yaml:"truncate_target"`
-	TruncateMethod          string      `yaml:"truncate_method"`
+	TruncateMethod       string      `yaml:"truncate_method"`
-	MaxPartitionErrrors     int         `yaml:"max_partition_errrors"`
+	Retry                RetryConfig `yaml:"retry"`
-	MaxExtractorBatchErrors int         `yaml:"max_extractor_batch_errors"`
+	RowsPerPartition     int64
-	Retry                   RetryConfig `yaml:"retry"`
+	ToStorage            ToStorageConfig `yaml:"to_storage"`
-	RowsPerPartition        int64
-	ToStorage               ToStorageConfig `yaml:"to_storage"`
 }
 
 type FromJsonItem struct {

internal/app/custom_errors/backoff.go

@@ -1,7 +1,6 @@
 package custom_errors
 
 import (
-	"context"
 	"math/rand"
 	"time"
 )
@@ -40,22 +39,3 @@ func ComputeBackoffDelay(retryCounter int, baseDelayMs int, maxDelayMs int, maxJ
 
 	return delay
 }
-
-func requeueWithBackoff(ctx context.Context, delay time.Duration, enqueue func()) {
-	if delay <= 0 {
-		enqueue()
-		return
-	}
-
-	go func() {
-		timer := time.NewTimer(delay)
-		defer timer.Stop()
-
-		select {
-		case <-ctx.Done():
-			return
-		case <-timer.C:
-			enqueue()
-		}
-	}()
-}

internal/app/custom_errors/loader.error.go

@@ -1,107 +0,0 @@
-package custom_errors
-
-import (
-	"context"
-	"fmt"
-	"sync"
-
-	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
-	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
-)
-
-type LoaderError struct {
-	Batch models.Batch
-	Msg   string
-}
-
-func (e *LoaderError) Error() string {
-	return e.Msg
-}
-
-func LoaderErrorHandler(
-	ctx context.Context,
-	retryConfig config.RetryConfig,
-	maxChunkErrors int,
-	chErrorsIn <-chan LoaderError,
-	chBatchesOut chan<- models.Batch,
-	chJobErrorsOut chan<- JobError,
-	wgActiveBatches *sync.WaitGroup,
-) {
-	definitiveErrors := 0
-
-	for {
-		if ctx.Err() != nil {
-			return
-		}
-
-		select {
-		case <-ctx.Done():
-			return
-
-		case err, ok := <-chErrorsIn:
-			if !ok {
-				return
-			}
-
-			if err.Batch.RetryCounter >= retryConfig.Attempts {
-				wgActiveBatches.Done()
-				definitiveErrors++
-				jobError := JobError{
-					ShouldCancelJob: false,
-					Msg:             fmt.Sprintf("Batch %v reached max retries (%d)", err.Batch.Id, retryConfig.Attempts),
-					Prev:            &err,
-				}
-
-				select {
-				case chJobErrorsOut <- jobError:
-				case <-ctx.Done():
-					return
-				}
-
-				if maxChunkErrors > 0 && definitiveErrors >= maxChunkErrors {
-					fatalError := JobError{
-						ShouldCancelJob: true,
-						Msg:             fmt.Sprintf("Chunk error limit reached (%d)", maxChunkErrors),
-						Prev:            &err,
-					}
-
-					select {
-					case chJobErrorsOut <- fatalError:
-					case <-ctx.Done():
-						return
-					}
-				}
-
-				continue
-			} else {
-				jobError := JobError{
-					ShouldCancelJob: false,
-					Msg:             fmt.Sprintf("Temporal error in batch %v (retries: %d)", err.Batch.Id, err.Batch.RetryCounter),
-					Prev:            &err,
-				}
-
-				select {
-				case chJobErrorsOut <- jobError:
-				case <-ctx.Done():
-					return
-				}
-			}
-
-			err.Batch.RetryCounter++
-			delay := ComputeBackoffDelay(
-				err.Batch.RetryCounter,
-				retryConfig.BaseDelayMs,
-				retryConfig.MaxDelayMs,
-				retryConfig.MaxJitterMs,
-			)
-
-			requeueWithBackoff(ctx, delay, func() {
-				select {
-				case chBatchesOut <- err.Batch:
-				case <-ctx.Done():
-					return
-				}
-			})
-		}
-	}
-}

internal/app/custom_errors/types.go

@@ -14,3 +14,12 @@ type ExtractorError struct {
 func (e *ExtractorError) Error() string {
 	return e.Msg
 }
+
+type LoaderError struct {
+	Batch models.Batch
+	Msg   string
+}
+
+func (e *LoaderError) Error() string {
+	return e.Msg
+}

internal/app/db-wrapper/mssql.go

@@ -10,7 +10,6 @@ import (
 	dbdialects "git.ksdemosapps.com/kylesoda/go-migrate/internal/app/db-wrapper/db_dialects"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
 	mssql "github.com/microsoft/go-mssqldb"
-	"github.com/sirupsen/logrus"
 )
 
 func init() {
@@ -188,8 +187,6 @@ func buildExtractQueryMssql(q ExtractionQuery) (string, error) {
 	hasRegularColumns := len(q.Columns) > 0
 	hasJsonColumns := len(q.FromJsonColumns) > 0
 
-	// logrus.Debugf("Extraction query: %+v", q)
-
 	resolvedJson := make(map[string][]config.FromJsonItem, len(q.FromJsonColumns))
 	if hasJsonColumns {
 		for _, jsonConfig := range q.FromJsonColumns {
@@ -296,7 +293,7 @@ func (mw *mssqlDbWrapper) QueryFromObject(ctx context.Context, q ExtractionQuery
 		return nil, err
 	}
 
-	logrus.Debugf("Query: %s", queryString)
+	// logrus.Debugf("Query: %s", queryString)
 
 	var queryArgs []any
 

internal/app/etl/extractors/consume.go

@@ -25,6 +25,7 @@ func (ex *GenericExtractor) Consume(
 	chErrorsOut chan<- custom_errors.JobError,
 	wgActivePartitions *sync.WaitGroup,
 	rowsRead *int64,
+	failedPartitionsCount *int32,
 	fromJsonColumns []config.FromJsonItem,
 ) {
 	indexPrimaryKey := slices.IndexFunc(columns, func(col models.ColumnType) bool {
@@ -72,11 +73,12 @@ func (ex *GenericExtractor) Consume(
 
 			if rowsReadResult > 0 {
 				current := atomic.LoadInt64(rowsRead)
-				logrus.Debugf("Rows read: +%v [current=%v] (%s.%s)", rowsReadResult, current, tableInfo.Schema, tableInfo.Table)
+				logrus.Debugf("Rows read (partition extracted): +%v [current=%v] (%s.%s)", rowsReadResult, current, tableInfo.Schema, tableInfo.Table)
 				atomic.AddInt64(rowsRead, int64(rowsReadResult))
 			}
 
 			if err != nil {
+				atomic.AddInt32(failedPartitionsCount, 1)
 				if jobError, ok := errors.AsType[*custom_errors.JobError](err); ok {
 					select {
 					case <-ctx.Done():
@@ -90,6 +92,16 @@ func (ex *GenericExtractor) Consume(
 					case chErrorsOut <- custom_errors.JobError{ShouldCancelJob: false, Msg: err.Error(), Prev: err}:
 					}
 				}
+
+				currentFPCount := atomic.LoadInt32(failedPartitionsCount)
+				if currentFPCount > int32(retryConfig.MaxFailedPartitions) {
+					select {
+					case <-ctx.Done():
+						return
+					case chErrorsOut <- custom_errors.JobError{ShouldCancelJob: true, Msg: "Max failed partitions reached"}:
+						return
+					}
+				}
 			}
 		}
 	}

internal/app/etl/extractors/process-with-retries.go

@@ -50,7 +50,7 @@ func (ex *GenericExtractor) ProcessPartitionWithRetries(
 
 			if currentParitition.RetryCounter >= retryConfig.Attempts {
 				return totalRowsRead, &custom_errors.JobError{
-					Msg:  fmt.Sprintf("Partition %v reached max retries", exError.Partition.Id),
+					Msg:  fmt.Sprintf("Partition %v reached max retries (%d)", currentParitition.Id, currentParitition.RetryCounter),
 					Prev: err,
 				}
 			}

internal/app/etl/loaders/consume.go

@@ -9,6 +9,8 @@ import (
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/custom_errors"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
+	"github.com/google/uuid"
+	"github.com/sirupsen/logrus"
 )
 
 func (gl *GenericLoader) Consume(
@@ -16,15 +18,77 @@ func (gl *GenericLoader) Consume(
 	tableInfo config.TargetTableInfo,
 	columns []models.ColumnType,
 	retryConfig config.RetryConfig,
+	batchSize int,
 	chBatchesIn <-chan models.Batch,
 	chErrorsOut chan<- custom_errors.JobError,
 	wgActiveBatches *sync.WaitGroup,
 	rowsLoaded *int64,
+	failedBatchesCount *int32,
 ) {
 	colNames := mapSlice(columns, func(col models.ColumnType) string {
 		return col.Name()
 	})
 
+	var accRows []models.UnknownRowValues
+	var parentBatchesId []uuid.UUID
+	pendingDone := 0
+
+	defer func() {
+		for range pendingDone {
+			wgActiveBatches.Done()
+		}
+	}()
+
+	flush := func() bool {
+		if len(accRows) == 0 {
+			return true
+		}
+		count := len(parentBatchesId)
+		superBatch := models.Batch{
+			Id:              uuid.New(),
+			ParentBatchesId: parentBatchesId,
+			Rows:            accRows,
+		}
+		processedRows, err := gl.ProcessBatchWithRetries(ctx, tableInfo, colNames, retryConfig, superBatch)
+		for range count {
+			wgActiveBatches.Done()
+		}
+		pendingDone -= count
+		accRows = nil
+		parentBatchesId = nil
+
+		if err != nil {
+			atomic.AddInt32(failedBatchesCount, 1)
+			if jobError, ok := errors.AsType[*custom_errors.JobError](err); ok {
+				select {
+				case <-ctx.Done():
+					return false
+				case chErrorsOut <- *jobError:
+				}
+			} else {
+				select {
+				case <-ctx.Done():
+					return false
+				case chErrorsOut <- custom_errors.JobError{ShouldCancelJob: false, Msg: err.Error(), Prev: err}:
+				}
+			}
+
+			if atomic.LoadInt32(failedBatchesCount) > int32(retryConfig.MaxFailedBatchesLoad) {
+				select {
+				case <-ctx.Done():
+				case chErrorsOut <- custom_errors.JobError{ShouldCancelJob: true, Msg: "Max failed batches (load) reached"}:
+				}
+				return false
+			}
+			return true
+		}
+
+		current := atomic.LoadInt64(rowsLoaded)
+		logrus.Debugf("Rows loaded (batch loaded): +%v [current=%v] (%s.%s)", processedRows, current, tableInfo.Schema, tableInfo.Table)
+		atomic.AddInt64(rowsLoaded, int64(processedRows))
+		return true
+	}
+
 	for {
 		if ctx.Err() != nil {
 			return
@@ -35,28 +99,55 @@ func (gl *GenericLoader) Consume(
 			return
 		case batch, ok := <-chBatchesIn:
 			if !ok {
+				flush()
 				return
 			}
 
-			processedRows, err := gl.ProcessBatchWithRetries(ctx, tableInfo, colNames, retryConfig, batch)
+			if batchSize <= 0 {
-			wgActiveBatches.Done()
+				processedRows, err := gl.ProcessBatchWithRetries(ctx, tableInfo, colNames, retryConfig, batch)
+				wgActiveBatches.Done()
 
-			if err != nil {
+				if err != nil {
-				if jobError, ok := errors.AsType[*custom_errors.JobError](err); ok {
+					atomic.AddInt32(failedBatchesCount, 1)
-					select {
+					if jobError, ok := errors.AsType[*custom_errors.JobError](err); ok {
-					case <-ctx.Done():
+						select {
-						return
+						case <-ctx.Done():
-					case chErrorsOut <- *jobError:
+							return
+						case chErrorsOut <- *jobError:
+						}
+					} else {
+						select {
+						case <-ctx.Done():
+							return
+						case chErrorsOut <- custom_errors.JobError{ShouldCancelJob: false, Msg: err.Error(), Prev: err}:
+						}
 					}
-				} else {
+
-					select {
+					if atomic.LoadInt32(failedBatchesCount) > int32(retryConfig.MaxFailedBatchesLoad) {
-					case <-ctx.Done():
+						select {
-						return
+						case <-ctx.Done():
-					case chErrorsOut <- custom_errors.JobError{ShouldCancelJob: false, Msg: err.Error(), Prev: err}:
+							return
+						case chErrorsOut <- custom_errors.JobError{ShouldCancelJob: true, Msg: "Max failed batches (load) reached"}:
+							return
+						}
 					}
+					continue
 				}
-			} else {
+
+				current := atomic.LoadInt64(rowsLoaded)
+				logrus.Debugf("Rows loaded: +%v [current=%v] (%s.%s)", processedRows, current, tableInfo.Schema, tableInfo.Table)
 				atomic.AddInt64(rowsLoaded, int64(processedRows))
+				continue
+			}
+
+			pendingDone++
+			accRows = append(accRows, batch.Rows...)
+			parentBatchesId = append(parentBatchesId, batch.Id)
+
+			if len(accRows) >= batchSize {
+				if !flush() {
+					return
+				}
 			}
 		}
 	}

internal/app/etl/loaders/process-with-retries.go

@@ -29,9 +29,8 @@ func (gl *GenericLoader) ProcessBatchWithRetries(
 
 			if batch.RetryCounter >= retryConfig.Attempts {
 				return rowsLoaded, &custom_errors.JobError{
-					ShouldCancelJob: false,
+					Msg:  fmt.Sprintf("Batch %v reached max retries (%d)", batch.Id, batch.RetryCounter),
-					Msg:             fmt.Sprintf("Temporal error in batch %v (retries: %d)", btError.Batch.Id, btError.Batch.RetryCounter),
+					Prev: btError,
-					Prev:            btError,
 				}
 			}
 

internal/app/etl/transformers/consume.go

@@ -0,0 +1,117 @@
+package transformers
+
+import (
+	"context"
+	"errors"
+	"sync"
+
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/custom_errors"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
+	"github.com/google/uuid"
+)
+
+func (mssqlTr *MssqlTransformer) Consume(
+	ctx context.Context,
+	columns []models.ColumnType,
+	retryConfig config.RetryConfig,
+	batchSize int,
+	chBatchesIn <-chan models.Batch,
+	chBatchesOut chan<- models.Batch,
+	chJobErrorsOut chan<- custom_errors.JobError,
+	wgActiveBatches *sync.WaitGroup,
+) {
+	transformationPlan := computeTransformationPlan(columns)
+	storagePlan := computeStorageTransformationPlan(ctx, mssqlTr.azureClient, mssqlTr.toStorage, columns, mssqlTr.sourceTable)
+	transformationPlan = append(transformationPlan, storagePlan...)
+
+	var accRows []models.UnknownRowValues
+	var parentBatchesId []uuid.UUID
+	var firstPartitionId uuid.UUID
+
+	flush := func() bool {
+		if len(accRows) == 0 {
+			return true
+		}
+		out := models.Batch{
+			Id:              uuid.New(),
+			PartitionId:     firstPartitionId,
+			ParentBatchesId: parentBatchesId,
+			Rows:            accRows,
+		}
+		select {
+		case chBatchesOut <- out:
+			wgActiveBatches.Add(1)
+		case <-ctx.Done():
+			return false
+		}
+		accRows = nil
+		parentBatchesId = nil
+		firstPartitionId = uuid.Nil
+		return true
+	}
+
+	for {
+		if ctx.Err() != nil {
+			return
+		}
+
+		select {
+		case <-ctx.Done():
+			return
+
+		case batch, ok := <-chBatchesIn:
+			if !ok {
+				flush()
+				return
+			}
+
+			if len(transformationPlan) > 0 {
+				err := ProcessBatchWithRetries(ctx, &batch, transformationPlan, retryConfig)
+				if err != nil {
+					if errors.Is(err, ctx.Err()) {
+						return
+					}
+
+					if jobError, ok := errors.AsType[*custom_errors.JobError](err); ok {
+						select {
+						case chJobErrorsOut <- *jobError:
+						case <-ctx.Done():
+							return
+						}
+					} else {
+						select {
+						case chJobErrorsOut <- custom_errors.JobError{ShouldCancelJob: true, Msg: "Transformation failed", Prev: err}:
+						case <-ctx.Done():
+							return
+						}
+					}
+
+					return
+				}
+			}
+
+			if batchSize <= 0 {
+				select {
+				case chBatchesOut <- batch:
+					wgActiveBatches.Add(1)
+				case <-ctx.Done():
+					return
+				}
+				continue
+			}
+
+			if len(parentBatchesId) == 0 {
+				firstPartitionId = batch.PartitionId
+			}
+			accRows = append(accRows, batch.Rows...)
+			parentBatchesId = append(parentBatchesId, batch.Id)
+
+			if len(accRows) >= batchSize {
+				if !flush() {
+					return
+				}
+			}
+		}
+	}
+}

internal/app/etl/transformers/mssql.go

@@ -1,20 +1,9 @@
 package transformers
 
 import (
-	"context"
-	"errors"
-	"fmt"
-	"strings"
-	"sync"
-	"time"
-
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/azure"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
-	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/custom_errors"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/etl"
-	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
-	"github.com/google/uuid"
-	log "github.com/sirupsen/logrus"
 )
 
 type MssqlTransformer struct {
@@ -30,196 +19,3 @@ func NewMssqlTransformer(toStorage config.ToStorageConfig, sourceTable config.So
 		azureClient: azureClient,
 	}
 }
-
-func computeTransformationPlan(columns []models.ColumnType) []etl.ColumnTransformPlan {
-	var plan []etl.ColumnTransformPlan
-
-	for i, col := range columns {
-		switch col.SystemType() {
-		case "uniqueidentifier":
-			plan = append(plan, etl.ColumnTransformPlan{
-				Index: i,
-				Fn: func(v any) (any, error) {
-					if b, ok := v.([]byte); ok && b != nil {
-						return mssqlUuidToBigEndian(b)
-					}
-					return v, nil
-				},
-			})
-
-		case "geometry", "geography":
-			plan = append(plan, etl.ColumnTransformPlan{
-				Index: i,
-				Fn: func(v any) (any, error) {
-					if b, ok := v.([]byte); ok && b != nil {
-						return wkbToEwkbWithSrid(b, 4326)
-					}
-					return v, nil
-				},
-			})
-
-		case "datetime", "datetime2":
-			plan = append(plan, etl.ColumnTransformPlan{
-				Index: i,
-				Fn: func(v any) (any, error) {
-					if t, ok := v.(time.Time); ok {
-						return ensureUTC(t), nil
-					}
-					return v, nil
-				},
-			})
-		}
-	}
-
-	return plan
-}
-
-func computeStorageTransformationPlan(
-	ctx context.Context,
-	azureClient *azure.Client,
-	toStorage config.ToStorageConfig,
-	sourceColumns []models.ColumnType,
-	sourceTable config.SourceTableInfo,
-) []etl.ColumnTransformPlan {
-	if azureClient == nil || len(toStorage.Columns) == 0 {
-		return nil
-	}
-
-	colIndex := make(map[string]int, len(sourceColumns))
-	for i, col := range sourceColumns {
-		colIndex[strings.ToUpper(col.Name())] = i
-	}
-
-	var plan []etl.ColumnTransformPlan
-	for _, storageCol := range toStorage.Columns {
-		if storageCol.Mode != "REFERENCE_ONLY" {
-			log.Warnf("to_storage: unsupported mode %q for column %s — skipping", storageCol.Mode, storageCol.Source)
-			continue
-		}
-
-		idx, ok := colIndex[strings.ToUpper(storageCol.Source)]
-		if !ok {
-			log.Warnf("to_storage: source column %q not found in source schema — skipping", storageCol.Source)
-			continue
-		}
-
-		sourceColName := storageCol.Source
-		schema := sourceTable.Schema
-		table := sourceTable.Table
-
-		plan = append(plan, etl.ColumnTransformPlan{
-			Index: idx,
-			Fn: func(v any) (any, error) {
-				if v == nil {
-					return nil, nil
-				}
-				b, ok := v.([]byte)
-				if !ok {
-					log.Warnf("to_storage: expected []byte for %s.%s.%s, got %T — passing through",
-						schema, table, sourceColName, v)
-					return v, nil
-				}
-				start := time.Now()
-				blobPath := fmt.Sprintf("%s/%s/%s", schema, table, uuid.New().String())
-				blobURL, err := azureClient.UploadAndGetURL(ctx, blobPath, b)
-				if err != nil {
-					return nil, fmt.Errorf("uploading %s.%s.%s: %w", schema, table, sourceColName, err)
-				}
-				log.Debugf(`Succesfully uploaded "%s", (%vms)`, blobURL, time.Since(start).Milliseconds())
-				return blobURL, nil
-			},
-		})
-	}
-	return plan
-}
-
-const processBatchCtxCheck = 4096
-
-func (mssqlTr *MssqlTransformer) ProcessBatch(
-	ctx context.Context,
-	batch *models.Batch,
-	transformationPlan []etl.ColumnTransformPlan,
-) error {
-	for i, rowValues := range batch.Rows {
-		if i%processBatchCtxCheck == 0 {
-			if err := ctx.Err(); err != nil {
-				return err
-			}
-		}
-
-		for _, task := range transformationPlan {
-			val := rowValues[task.Index]
-			if val == nil {
-				continue
-			}
-
-			transformed, err := task.Fn(val)
-			if err != nil {
-				return err
-			}
-			rowValues[task.Index] = transformed
-		}
-	}
-
-	return nil
-}
-
-func (mssqlTr *MssqlTransformer) Exec(
-	ctx context.Context,
-	columns []models.ColumnType,
-	chBatchesIn <-chan models.Batch,
-	chBatchesOut chan<- models.Batch,
-	chJobErrorsOut chan<- custom_errors.JobError,
-	wgActiveBatches *sync.WaitGroup,
-) {
-	transformationPlan := computeTransformationPlan(columns)
-	storagePlan := computeStorageTransformationPlan(ctx, mssqlTr.azureClient, mssqlTr.toStorage, columns, mssqlTr.sourceTable)
-	transformationPlan = append(transformationPlan, storagePlan...)
-
-	for {
-		if ctx.Err() != nil {
-			return
-		}
-
-		select {
-		case <-ctx.Done():
-			return
-
-		case batch, ok := <-chBatchesIn:
-			if !ok {
-				return
-			}
-
-			if len(transformationPlan) == 0 {
-				select {
-				case chBatchesOut <- batch:
-					wgActiveBatches.Add(1)
-					continue
-				case <-ctx.Done():
-					return
-				}
-			}
-
-			err := mssqlTr.ProcessBatch(ctx, &batch, transformationPlan)
-			if err != nil {
-				if errors.Is(err, ctx.Err()) {
-					return
-				}
-
-				select {
-				case chJobErrorsOut <- custom_errors.JobError{ShouldCancelJob: true, Msg: "Transformation failed", Prev: err}:
-				case <-ctx.Done():
-				}
-				return
-			}
-
-			select {
-			case chBatchesOut <- batch:
-			case <-ctx.Done():
-				return
-			}
-
-			wgActiveBatches.Add(1)
-		}
-	}
-}

internal/app/etl/transformers/plan.go

@@ -0,0 +1,122 @@
+package transformers
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/azure"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/custom_errors"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/etl"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
+	"github.com/google/uuid"
+	"github.com/sirupsen/logrus"
+)
+
+func computeTransformationPlan(columns []models.ColumnType) []etl.ColumnTransformPlan {
+	var plan []etl.ColumnTransformPlan
+
+	for i, col := range columns {
+		switch col.SystemType() {
+		case "uniqueidentifier":
+			plan = append(plan, etl.ColumnTransformPlan{
+				Index: i,
+				Fn: func(v any) (any, error) {
+					if b, ok := v.([]byte); ok && b != nil {
+						return mssqlUuidToBigEndian(b)
+					}
+					return v, nil
+				},
+			})
+
+		case "geometry", "geography":
+			plan = append(plan, etl.ColumnTransformPlan{
+				Index: i,
+				Fn: func(v any) (any, error) {
+					if b, ok := v.([]byte); ok && b != nil {
+						return wkbToEwkbWithSrid(b, 4326)
+					}
+					return v, nil
+				},
+			})
+
+		case "datetime", "datetime2":
+			plan = append(plan, etl.ColumnTransformPlan{
+				Index: i,
+				Fn: func(v any) (any, error) {
+					if t, ok := v.(time.Time); ok {
+						return ensureUTC(t), nil
+					}
+					return v, nil
+				},
+			})
+		}
+	}
+
+	return plan
+}
+
+func computeStorageTransformationPlan(
+	ctx context.Context,
+	azureClient *azure.Client,
+	toStorage config.ToStorageConfig,
+	sourceColumns []models.ColumnType,
+	sourceTable config.SourceTableInfo,
+) []etl.ColumnTransformPlan {
+	if azureClient == nil || len(toStorage.Columns) == 0 {
+		return nil
+	}
+
+	colIndex := make(map[string]int, len(sourceColumns))
+	for i, col := range sourceColumns {
+		colIndex[strings.ToUpper(col.Name())] = i
+	}
+
+	var plan []etl.ColumnTransformPlan
+	for _, storageCol := range toStorage.Columns {
+		if storageCol.Mode != "REFERENCE_ONLY" {
+			logrus.Warnf("to_storage: unsupported mode %q for column %s — skipping", storageCol.Mode, storageCol.Source)
+			continue
+		}
+
+		idx, ok := colIndex[strings.ToUpper(storageCol.Source)]
+		if !ok {
+			logrus.Warnf("to_storage: source column %q not found in source schema — skipping", storageCol.Source)
+			continue
+		}
+
+		sourceColName := storageCol.Source
+		schema := sourceTable.Schema
+		table := sourceTable.Table
+
+		plan = append(plan, etl.ColumnTransformPlan{
+			Index: idx,
+			Fn: func(v any) (any, error) {
+				if v == nil {
+					return nil, nil
+				}
+				b, ok := v.([]byte)
+				if !ok {
+					logrus.Warnf("to_storage: expected []byte for %s.%s.%s, got %T — passing through",
+						schema, table, sourceColName, v)
+					return v, nil
+				}
+				// start := time.Now()
+				blobPath := fmt.Sprintf("%s/%s/%s", schema, table, uuid.New().String())
+				blobURL, err := azureClient.UploadAndGetURL(ctx, blobPath, b)
+				if err != nil {
+					return nil, &custom_errors.JobError{
+						Msg:  fmt.Sprintf("Error uploading %s.%s.%s", schema, table, sourceColName),
+						Prev: err,
+					}
+				}
+
+				// logrus.Debugf(`Succesfully uploaded "%s", (%vms)`, blobURL, time.Since(start).Milliseconds())
+				return blobURL, nil
+			},
+		})
+	}
+	return plan
+}

internal/app/etl/transformers/process-with-retries.go

@@ -0,0 +1,73 @@
+package transformers
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/custom_errors"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/etl"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
+)
+
+const processBatchCtxCheck = 4096
+
+func ProcessBatchWithRetries(
+	ctx context.Context,
+	batch *models.Batch,
+	transformationPlan []etl.ColumnTransformPlan,
+	retryConfig config.RetryConfig,
+) error {
+	for i, rowValues := range batch.Rows {
+		if i%processBatchCtxCheck == 0 {
+			if err := ctx.Err(); err != nil {
+				return err
+			}
+		}
+
+		for _, task := range transformationPlan {
+			val := rowValues[task.Index]
+			if val == nil {
+				continue
+			}
+
+			var lastErr error
+			success := false
+
+			for attempt := 0; attempt < retryConfig.Attempts; attempt++ {
+				transformed, err := task.Fn(val)
+				if err == nil {
+					rowValues[task.Index] = transformed
+					success = true
+					break
+				}
+
+				lastErr = err
+				if jobError, ok := errors.AsType[*custom_errors.JobError](err); ok {
+					if jobError.ShouldCancelJob {
+						return jobError
+					}
+				}
+
+				if attempt == retryConfig.Attempts-1 {
+					break
+				}
+
+				delay := custom_errors.ComputeBackoffDelay(
+					attempt,
+					retryConfig.BaseDelayMs,
+					retryConfig.MaxDelayMs,
+					retryConfig.MaxJitterMs,
+				)
+				time.Sleep(delay)
+			}
+
+			if !success {
+				return lastErr
+			}
+		}
+	}
+
+	return nil
+}

internal/app/etl/transformers/types.go

@@ -1 +0,0 @@
-package transformers

internal/app/etl/types.go

@@ -9,18 +9,6 @@ import (
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
 )
 
-type Extractor interface {
-	ProcessPartition(
-		ctx context.Context,
-		tableInfo config.SourceTableInfo,
-		columns []models.ColumnType,
-		batchSize int,
-		partition models.Partition,
-		indexPrimaryKey int,
-		chBatchesOut chan<- models.Batch,
-	) (int, error)
-}
-
 type TransformerFunc func(any) (any, error)
 
 type ColumnTransformPlan struct {
@@ -29,31 +17,18 @@ type ColumnTransformPlan struct {
 }
 
 type Transformer interface {
-	ProcessBatch(
+	Consume(
-		ctx context.Context,
-		batch *models.Batch,
-		transformationPlan []ColumnTransformPlan,
-	) error
-
-	Exec(
 		ctx context.Context,
 		columns []models.ColumnType,
+		retryConfig config.RetryConfig,
+		batchSize int,
 		chBatchesIn <-chan models.Batch,
-		chBactchesOut chan<- models.Batch,
+		chBatchesOut chan<- models.Batch,
 		chJobErrorsOut chan<- custom_errors.JobError,
 		wgActiveBatches *sync.WaitGroup,
 	)
 }
 
-type Loader interface {
-	ProcessBatch(
-		ctx context.Context,
-		tableInfo config.TargetTableInfo,
-		colNames []string,
-		batch models.Batch,
-	) (int64, error)
-}
-
 type TableAnalyzer interface {
 	QueryColumnTypes(
 		ctx context.Context,

internal/app/models/main.go

@@ -9,10 +9,11 @@ import (
 type UnknownRowValues = []any
 
 type Batch struct {
-	Id           uuid.UUID
+	Id              uuid.UUID
-	PartitionId  uuid.UUID
+	PartitionId     uuid.UUID
-	Rows         []UnknownRowValues
+	ParentBatchesId []uuid.UUID
-	RetryCounter int
+	Rows            []UnknownRowValues
+	RetryCounter    int
 }
 
 type PartitionRange struct {

scripts/mssql-copy-in/main.go

@@ -12,9 +12,10 @@ import (
 )
 
 const (
-	totalRows int    = 1_000_000
+	// totalRows int = 1_000_000
-	chunkSize int    = 50_000
+	totalRows int = 1000
-	queueSize int    = 4
+	chunkSize int = 200
+	queueSize int = 4
 )
 
 func main() {
@@ -40,6 +41,14 @@ func main() {
 		seedManzanas(ctx, db)
 	})
 
+	wgSeed.Go(func() {
+		seedPuertos(ctx, db)
+	})
+
+	wgSeed.Go(func() {
+		seedSiteHolderAttach(ctx, db)
+	})
+
 	wgSeed.Wait()
 }
 

scripts/mssql-copy-in/site-holder-attach.go

@@ -0,0 +1,227 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"database/sql"
+	"fmt"
+	"math/rand"
+	"sync"
+	"time"
+
+	"github.com/google/uuid"
+	log "github.com/sirupsen/logrus"
+)
+
+var siteHolderAttachJob = MigrationJob{
+	Schema: "Infraestructura",
+	Table:  "SITE_HOLDER__ATTACH",
+}
+
+func seedSiteHolderAttach(ctx context.Context, db *sql.DB) error {
+	maxOid, err := getMaxGDBArchiveOidForAttach(ctx, db)
+	if err != nil {
+		log.Fatal("Error getting max GDB_ARCHIVE_OID: ", err)
+	}
+
+	log.Infof("Starting SITE_HOLDER__ATTACH data generation from GDB_ARCHIVE_OID: %d", maxOid+1)
+
+	rowsChan := make(chan []UnknownRowValues, queueSize)
+
+	var wgRowGenerator sync.WaitGroup
+
+	wgRowGenerator.Go(func() {
+		generateSiteHolderAttachRows(ctx, maxOid, totalRows, chunkSize, rowsChan)
+	})
+
+	columns := []string{
+		"GDB_ARCHIVE_OID",
+		"REL_GLOBALID",
+		"CONTENT_TYPE",
+		"ATT_NAME",
+		"DATA_SIZE",
+		"DATA",
+		"GLOBALID",
+		"GDB_FROM_DATE",
+		"GDB_TO_DATE",
+		"ATTACHMENTID",
+	}
+
+	if err := loadRowsMssql(ctx, siteHolderAttachJob, columns, db, rowsChan); err != nil {
+		return fmt.Errorf("Error loading rows (SITE_HOLDER__ATTACH): %w", err)
+	}
+
+	log.Info("Data generation and loading completed successfully (SITE_HOLDER__ATTACH)")
+	wgRowGenerator.Wait()
+
+	return nil
+}
+
+func getMaxGDBArchiveOidForAttach(ctx context.Context, db *sql.DB) (int, error) {
+	var maxOid sql.NullInt64
+
+	query := fmt.Sprintf(`
+		SELECT ISNULL(MAX(GDB_ARCHIVE_OID), 0)
+		FROM [%s].[%s]
+	`, siteHolderAttachJob.Schema, siteHolderAttachJob.Table)
+
+	err := db.QueryRowContext(ctx, query).Scan(&maxOid)
+	if err != nil && err != sql.ErrNoRows {
+		return 0, err
+	}
+
+	if !maxOid.Valid {
+		return 0, nil
+	}
+
+	return int(maxOid.Int64), nil
+}
+
+func generateSiteHolderAttachRows(
+	ctx context.Context,
+	startOid int,
+	totalRows int,
+	chunkSize int,
+	out chan<- []UnknownRowValues,
+) {
+	defer close(out)
+
+	rowsGenerated := 0
+	currentChunk := make([]UnknownRowValues, 0, chunkSize)
+
+	for i := range totalRows {
+		gdbArchiveOid := startOid + i + 1
+		row := generateSiteHolderAttachRow(gdbArchiveOid)
+		currentChunk = append(currentChunk, row)
+		rowsGenerated++
+
+		if len(currentChunk) == chunkSize {
+			select {
+			case out <- currentChunk:
+				log.Debugf("Sent SITE_HOLDER__ATTACH chunk with %d rows", len(currentChunk))
+			case <-ctx.Done():
+				log.Info("Context cancelled, stopping SITE_HOLDER__ATTACH row generation")
+				return
+			}
+			currentChunk = make([]UnknownRowValues, 0, chunkSize)
+		}
+
+		if rowsGenerated%100_000 == 0 {
+			logSiteHolderAttachSampleRow(rowsGenerated, row)
+		}
+	}
+
+	if len(currentChunk) > 0 {
+		select {
+		case out <- currentChunk:
+			log.Debugf("Sent final SITE_HOLDER__ATTACH chunk with %d rows", len(currentChunk))
+		case <-ctx.Done():
+			log.Info("Context cancelled, stopping SITE_HOLDER__ATTACH row generation")
+		}
+	}
+
+	log.Infof("Finished generating %d SITE_HOLDER__ATTACH rows", rowsGenerated)
+}
+
+func generateSiteHolderAttachRow(gdbArchiveOid int) UnknownRowValues {
+	dateLowerLimit, _ := time.Parse(time.RFC3339, "2020-12-31T23:59:59Z")
+	dateUpperLimit, _ := time.Parse(time.RFC3339, "2025-12-31T23:59:59Z")
+
+	relGlobalID, _ := uuid.New().MarshalBinary()
+	contentType := generateRandomContentType()
+	attName := generateRandomAttachmentName()
+	binaryData := generateRandomBinaryContent()
+	dataSize := len(binaryData)
+	globalID, _ := uuid.New().MarshalBinary()
+	gdbFromDate := generateRandomTimestamp(dateLowerLimit, dateUpperLimit)
+	gdbToDate, _ := time.Parse(time.RFC3339, "9999-12-31T23:59:59Z")
+	attachmentID := rand.Intn(10000) + 1
+
+	return UnknownRowValues{
+		gdbArchiveOid,
+		relGlobalID,
+		contentType,
+		attName,
+		dataSize,
+		binaryData,
+		globalID,
+		gdbFromDate,
+		gdbToDate,
+		attachmentID,
+	}
+}
+
+func generateRandomContentType() string {
+	contentTypes := []string{
+		"text/plain",
+		"application/pdf",
+		"image/jpeg",
+		"image/png",
+		"application/msword",
+		"application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+		"text/csv",
+		"application/json",
+	}
+	return contentTypes[rand.Intn(len(contentTypes))]
+}
+
+func generateRandomAttachmentName() string {
+	extensions := []string{".txt", ".pdf", ".jpg", ".png", ".doc", ".docx", ".csv", ".json"}
+	baseName := generateRandomString(20)
+	extension := extensions[rand.Intn(len(extensions))]
+	return baseName + extension
+}
+
+func generateRandomBinaryContent() []byte {
+	sizeOptions := []int{100, 500, 1000, 5000, 10000, 50000, 100000}
+	size := sizeOptions[rand.Intn(len(sizeOptions))]
+
+	var buf bytes.Buffer
+
+	lineCount := rand.Intn(size/50) + 1
+	for range lineCount {
+		line := generateRandomString(rand.Intn(80) + 20)
+		buf.WriteString(line)
+		buf.WriteString("\n")
+	}
+
+	for buf.Len() < size {
+		randomText := generateRandomString(rand.Intn(100) + 50)
+		buf.WriteString(randomText)
+		buf.WriteString("\n")
+	}
+
+	result := buf.Bytes()
+	if len(result) > size {
+		result = result[:size]
+	}
+
+	return result
+}
+
+func logSiteHolderAttachSampleRow(id int, rowValues UnknownRowValues) {
+	dataBytes := rowValues[5].([]byte)
+	log.Infof(`
+Sample SITE_HOLDER__ATTACH row #%d:
+GDB_ARCHIVE_OID: %v
+REL_GLOBALID: [binary UUID]
+CONTENT_TYPE: %v
+ATT_NAME: %v
+DATA_SIZE: %v
+DATA: [%d bytes of binary content]
+GLOBALID: [binary UUID]
+GDB_FROM_DATE: %v
+GDB_TO_DATE: %v
+ATTACHMENTID: %v
+`,
+		id,
+		rowValues[0],
+		rowValues[2],
+		rowValues[3],
+		rowValues[4],
+		len(dataBytes),
+		rowValues[7],
+		rowValues[8],
+		rowValues[9],
+	)
+}