Files
go-migrate/internal/app/etl/table_analyzers/mssql.go

106 lines
2.5 KiB
Go

package table_analyzers
import (
"context"
"database/sql"
"fmt"
"time"
"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/etl"
"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
"github.com/google/uuid"
)
type MssqlTableAnalyzer struct {
db *sql.DB
}
func NewMssqlTableAnalyzer(db *sql.DB) etl.TableAnalyzer {
return &MssqlTableAnalyzer{db: db}
}
func (ta *MssqlTableAnalyzer) QueryColumnTypes(
ctx context.Context,
tableInfo config.TableInfo,
) ([]models.ColumnType, error) {
return []models.ColumnType{}, nil
}
func (ta *MssqlTableAnalyzer) EstimateTotalRows(
ctx context.Context,
tableInfo config.TableInfo,
) (int64, error) {
query := `
SELECT SUM(p.rows) AS count
FROM sys.tables t
JOIN sys.schemas s ON t.schema_id = s.schema_id
JOIN sys.partitions p ON t.object_id = p.object_id
WHERE s.name = @schema AND t.name = @table AND p.index_id IN (0, 1)
GROUP BY t.name`
ctxTimeout, cancel := context.WithTimeout(ctx, time.Second*20)
defer cancel()
var rowsCount int64
err := ta.db.QueryRowContext(ctxTimeout, query, sql.Named("schema", tableInfo.Schema), sql.Named("table", tableInfo.Table)).Scan(&rowsCount)
if err != nil {
return 0, err
}
return rowsCount, nil
}
func (ta *MssqlTableAnalyzer) CalculatePartitionRanges(
ctx context.Context,
tableInfo config.TableInfo,
partitionColumn string,
maxPartitions int64,
) ([]models.Partition, error) {
query := fmt.Sprintf(`
SELECT
MIN([%s]) AS lower_limit,
MAX([%s]) AS upper_limit
FROM (SELECT [%s], NTILE(@maxPartitions) OVER (ORDER BY [%s]) AS batch_id FROM [%s].[%s]) AS T
GROUP BY batch_id
ORDER BY batch_id`,
partitionColumn,
partitionColumn,
partitionColumn,
partitionColumn,
tableInfo.Schema,
tableInfo.Table)
ctxTimeout, cancel := context.WithTimeout(ctx, time.Second*20)
defer cancel()
rows, err := ta.db.QueryContext(ctxTimeout, query, sql.Named("maxPartitions", maxPartitions))
if err != nil {
return nil, err
}
defer rows.Close()
partitions := make([]models.Partition, 0, maxPartitions)
for rows.Next() {
partition := models.Partition{
Id: uuid.New(),
ShouldUseRange: true,
RetryCounter: 0,
IsLowerLimitInclusive: true,
}
if err := rows.Scan(&partition.LowerLimit, &partition.UpperLimit); err != nil {
return nil, err
}
partitions = append(partitions, partition)
}
if err := rows.Err(); err != nil {
return nil, err
}
return partitions, nil
}