Update bigquery table structure based on source postgresql table

Simple golang program which compares structure of the source PostgreSQL table with target table on Bigquery. If Bigquery table misses some columns schema is updated. I removed some parts so program as it is listed below does not work immediately. But it can be used as an inspiration.

package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"path/filepath"

	"google.golang.org/api/iterator"

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

func main() {

	paramDebug := flag.Bool("debug", false, "print debug messages")
	paramDebugLevel := flag.Int("debug_level", 0, "level of debug messages: 0 = default, common messages from run / 1 = show variables, queries etc. / 2 = deep debug, shows inserted data etc.")
	paramHelp := flag.Bool("help", false, "print help")
	paramBqDataset := flag.String("bqdataset", "", "name of dataset on bigquery / mask of the name")
	paramBqTable := flag.String("bqtable", "", "name of table on bigquery / mask of the name")
	flag.Parse()

	pcg.PrintDebugMsg = *paramDebug
	pcg.DebugLevel = *paramDebugLevel
	printHelpMsg := *paramHelp
	bqDatasetID := *paramBqDataset
	bqTable := *paramBqTable
	pcg.DebugMsg(1, fmt.Sprintf("pcg.PrintDebugMsg: %v", pcg.PrintDebugMsg))
	pcg.DebugMsg(1, fmt.Sprintf("printHelpMsg: %v", printHelpMsg))
	pcg.DebugMsg(1, fmt.Sprintf("bqDatasetID: %s", bqDatasetID))
	pcg.DebugMsg(1, fmt.Sprintf("bqTable: %s", bqTable))

	if printHelpMsg == true {
		flag.PrintDefaults()
		log.Fatal()
	}

	ctx := context.Background()
	bqDB, err := bigquery.NewClient(ctx, pcg.ProjectID)
	if err != nil {
		log.Fatalln("Cannot create new BQ client: ", err)
	}

	var tableMatch bool
	bqdatasets := bqDB.Datasets(ctx)
	for {
		dataset, err := bqdatasets.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			log.Fatalf("Cannot not iterate over datasets %s: %s", dataset, err.Error())
		}
		datasetName := dataset.DatasetID
		pcg.DebugMsg(1, "dataset: ", datasetName)

		if bqDatasetID == "" || ((bqDatasetID != "") && (bqDatasetID == datasetName)) {
			datasetMeta, err := dataset.Metadata(ctx)
			if err == nil {
				pcg.DebugMsg(2, "dataset meta: ", datasetMeta.Name, " - ", datasetMeta.Location)
			} else {
				pcg.PrintMsg("error in checking dataset metadata: ", err)
			}

			bqtables := dataset.Tables(ctx)
			for {
				table, err := bqtables.Next()
				if err == iterator.Done {
					break
				}
				if err != nil {
					log.Fatalf("Cannot not iterate over table %s: %s", table, err.Error())
				}
				tableName := table.TableID
				pcg.DebugMsg(1, "table: ", tableName)

				if bqTable != "" {
					tableMatch, err = filepath.Match(bqTable, tableName)
					if err != nil {
						log.Fatal("cannot check table name match: ", err)
					}
					pcg.DebugMsg(2, "tableMatch: ", tableMatch)
				}

				if bqTable == "" || ((bqTable != "") && (tableMatch == true)) {
					tableMeta, err := table.Metadata(ctx)
					if err == nil {
						sch := tableMeta.Schema
						pcg.DebugMsg(2, "columns: ", len(sch))
						for i := range sch {
							col := sch[i]
							pcg.DebugMsg(2, "columns: ", i, ": ", col.Name, " - ", col.Required, " - ", col.Type)
							if col.Required == true {
								pcg.PrintMsg(dataset.DatasetID, ".", table.TableID, " - ", col.Name)
							}
						}
					} else {
						pcg.PrintMsg("error in checking table metadata: ", err)
					}
				}
			}
		}
	}
}