// ReadMigrationMaxValues returns the maximum values to be iterated on rowcopy
func (this *Applier) ReadMigrationMaxValues(uniqueKey *sql.UniqueKey) error {
log.Debugf("Reading migration range according to key: %s", uniqueKey.Name)
query, err := sql.BuildUniqueKeyMaxValuesPreparedQuery(this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, uniqueKey.Columns.Names)
if err != nil {
return err
}
rows, err := this.db.Query(query)
if err != nil {
return err
}
for rows.Next() {
this.migrationContext.MigrationRangeMaxValues = sql.NewColumnValues(uniqueKey.Len())
if err = rows.Scan(this.migrationContext.MigrationRangeMaxValues.ValuesPointers...); err != nil {
return err
}
}
log.Infof("Migration max values: [%s]", this.migrationContext.MigrationRangeMaxValues)
return err
}
// CalculateNextIterationRangeEndValues reads the next-iteration-range-end unique key values,
// which will be used for copying the next chunk of rows. Ir returns "false" if there is
// no further chunk to work through, i.e. we're past the last chunk and are done with
// itrating the range (and this done with copying row chunks)
func (this *Applier) CalculateNextIterationRangeEndValues() (hasFurtherRange bool, err error) {
this.migrationContext.MigrationIterationRangeMinValues = this.migrationContext.MigrationIterationRangeMaxValues
if this.migrationContext.MigrationIterationRangeMinValues == nil {
this.migrationContext.MigrationIterationRangeMinValues = this.migrationContext.MigrationRangeMinValues
}
query, explodedArgs, err := sql.BuildUniqueKeyRangeEndPreparedQuery(
this.migrationContext.DatabaseName,
this.migrationContext.OriginalTableName,
this.migrationContext.UniqueKey.Columns.Names,
this.migrationContext.MigrationIterationRangeMinValues.AbstractValues(),
this.migrationContext.MigrationRangeMaxValues.AbstractValues(),
atomic.LoadInt64(&this.migrationContext.ChunkSize),
this.migrationContext.GetIteration() == 0,
fmt.Sprintf("iteration:%d", this.migrationContext.GetIteration()),
)
if err != nil {
return hasFurtherRange, err
}
rows, err := this.db.Query(query, explodedArgs...)
if err != nil {
return hasFurtherRange, err
}
iterationRangeMaxValues := sql.NewColumnValues(this.migrationContext.UniqueKey.Len())
for rows.Next() {
if err = rows.Scan(iterationRangeMaxValues.ValuesPointers...); err != nil {
return hasFurtherRange, err
}
hasFurtherRange = true
}
if !hasFurtherRange {
log.Debugf("Iteration complete: no further range to iterate")
return hasFurtherRange, nil
}
this.migrationContext.MigrationIterationRangeMaxValues = iterationRangeMaxValues
return hasFurtherRange, nil
}