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// Copyright 2015 Google LLC
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
package bigquery
import (
bq ""
// QueryConfig holds the configuration for a query job.
type QueryConfig struct {
// Dst is the table into which the results of the query will be written.
// If this field is nil, a temporary table will be created.
Dst *Table
// The query to execute. See for details.
Q string
// DefaultProjectID and DefaultDatasetID specify the dataset to use for unqualified table names in the query.
// If DefaultProjectID is set, DefaultDatasetID must also be set.
DefaultProjectID string
DefaultDatasetID string
// TableDefinitions describes data sources outside of BigQuery.
// The map keys may be used as table names in the query string.
// When a QueryConfig is returned from Job.Config, the map values
// are always of type *ExternalDataConfig.
TableDefinitions map[string]ExternalData
// CreateDisposition specifies the circumstances under which the destination table will be created.
// The default is CreateIfNeeded.
CreateDisposition TableCreateDisposition
// WriteDisposition specifies how existing data in the destination table is treated.
// The default is WriteEmpty.
WriteDisposition TableWriteDisposition
// DisableQueryCache prevents results being fetched from the query cache.
// If this field is false, results are fetched from the cache if they are available.
// The query cache is a best-effort cache that is flushed whenever tables in the query are modified.
// Cached results are only available when TableID is unspecified in the query's destination Table.
// For more information, see
DisableQueryCache bool
// DisableFlattenedResults prevents results being flattened.
// If this field is false, results from nested and repeated fields are flattened.
// DisableFlattenedResults implies AllowLargeResults
// For more information, see
DisableFlattenedResults bool
// AllowLargeResults allows the query to produce arbitrarily large result tables.
// The destination must be a table.
// When using this option, queries will take longer to execute, even if the result set is small.
// For additional limitations, see
AllowLargeResults bool
// Priority specifies the priority with which to schedule the query.
// The default priority is InteractivePriority.
// For more information, see
Priority QueryPriority
// MaxBillingTier sets the maximum billing tier for a Query.
// Queries that have resource usage beyond this tier will fail (without
// incurring a charge). If this field is zero, the project default will be used.
MaxBillingTier int
// MaxBytesBilled limits the number of bytes billed for
// this job. Queries that would exceed this limit will fail (without incurring
// a charge).
// If this field is less than 1, the project default will be
// used.
MaxBytesBilled int64
// UseStandardSQL causes the query to use standard SQL. The default.
// Deprecated: use UseLegacySQL.
UseStandardSQL bool
// UseLegacySQL causes the query to use legacy SQL.
UseLegacySQL bool
// Parameters is a list of query parameters. The presence of parameters
// implies the use of standard SQL.
// If the query uses positional syntax ("?"), then no parameter may have a name.
// If the query uses named syntax ("@p"), then all parameters must have names.
// It is illegal to mix positional and named syntax.
Parameters []QueryParameter
// TimePartitioning specifies time-based partitioning
// for the destination table.
TimePartitioning *TimePartitioning
// RangePartitioning specifies integer range-based partitioning
// for the destination table.
RangePartitioning *RangePartitioning
// Clustering specifies the data clustering configuration for the destination table.
Clustering *Clustering
// The labels associated with this job.
Labels map[string]string
// If true, don't actually run this job. A valid query will return a mostly
// empty response with some processing statistics, while an invalid query will
// return the same error it would if it wasn't a dry run.
// Query.Read will fail with dry-run queries. Call Query.Run instead, and then
// call LastStatus on the returned job to get statistics. Calling Status on a
// dry-run job will fail.
DryRun bool
// Custom encryption configuration (e.g., Cloud KMS keys).
DestinationEncryptionConfig *EncryptionConfig
// Allows the schema of the destination table to be updated as a side effect of
// the query job.
SchemaUpdateOptions []string
func (qc *QueryConfig) toBQ() (*bq.JobConfiguration, error) {
qconf := &bq.JobConfigurationQuery{
Query: qc.Q,
CreateDisposition: string(qc.CreateDisposition),
WriteDisposition: string(qc.WriteDisposition),
AllowLargeResults: qc.AllowLargeResults,
Priority: string(qc.Priority),
MaximumBytesBilled: qc.MaxBytesBilled,
TimePartitioning: qc.TimePartitioning.toBQ(),
RangePartitioning: qc.RangePartitioning.toBQ(),
Clustering: qc.Clustering.toBQ(),
DestinationEncryptionConfiguration: qc.DestinationEncryptionConfig.toBQ(),
SchemaUpdateOptions: qc.SchemaUpdateOptions,
if len(qc.TableDefinitions) > 0 {
qconf.TableDefinitions = make(map[string]bq.ExternalDataConfiguration)
for name, data := range qc.TableDefinitions {
qconf.TableDefinitions[name] = data.toBQ()
if qc.DefaultProjectID != "" || qc.DefaultDatasetID != "" {
qconf.DefaultDataset = &bq.DatasetReference{
DatasetId: qc.DefaultDatasetID,
ProjectId: qc.DefaultProjectID,
if tier := int64(qc.MaxBillingTier); tier > 0 {
qconf.MaximumBillingTier = &tier
f := false
if qc.DisableQueryCache {
qconf.UseQueryCache = &f
if qc.DisableFlattenedResults {
qconf.FlattenResults = &f
// DisableFlattenResults implies AllowLargeResults.
qconf.AllowLargeResults = true
if qc.UseStandardSQL && qc.UseLegacySQL {
return nil, errors.New("bigquery: cannot provide both UseStandardSQL and UseLegacySQL")
if len(qc.Parameters) > 0 && qc.UseLegacySQL {
return nil, errors.New("bigquery: cannot provide both Parameters (implying standard SQL) and UseLegacySQL")
ptrue := true
pfalse := false
if qc.UseLegacySQL {
qconf.UseLegacySql = &ptrue
} else {
qconf.UseLegacySql = &pfalse
if qc.Dst != nil && !qc.Dst.implicitTable() {
qconf.DestinationTable = qc.Dst.toBQ()
for _, p := range qc.Parameters {
qp, err := p.toBQ()
if err != nil {
return nil, err
qconf.QueryParameters = append(qconf.QueryParameters, qp)
return &bq.JobConfiguration{
Labels: qc.Labels,
DryRun: qc.DryRun,
Query: qconf,
}, nil
func bqToQueryConfig(q *bq.JobConfiguration, c *Client) (*QueryConfig, error) {
qq := q.Query
qc := &QueryConfig{
Labels: q.Labels,
DryRun: q.DryRun,
Q: qq.Query,
CreateDisposition: TableCreateDisposition(qq.CreateDisposition),
WriteDisposition: TableWriteDisposition(qq.WriteDisposition),
AllowLargeResults: qq.AllowLargeResults,
Priority: QueryPriority(qq.Priority),
MaxBytesBilled: qq.MaximumBytesBilled,
UseLegacySQL: qq.UseLegacySql == nil || *qq.UseLegacySql,
TimePartitioning: bqToTimePartitioning(qq.TimePartitioning),
RangePartitioning: bqToRangePartitioning(qq.RangePartitioning),
Clustering: bqToClustering(qq.Clustering),
DestinationEncryptionConfig: bqToEncryptionConfig(qq.DestinationEncryptionConfiguration),
SchemaUpdateOptions: qq.SchemaUpdateOptions,
qc.UseStandardSQL = !qc.UseLegacySQL
if len(qq.TableDefinitions) > 0 {
qc.TableDefinitions = make(map[string]ExternalData)
for name, qedc := range qq.TableDefinitions {
edc, err := bqToExternalDataConfig(&qedc)
if err != nil {
return nil, err
qc.TableDefinitions[name] = edc
if qq.DefaultDataset != nil {
qc.DefaultProjectID = qq.DefaultDataset.ProjectId
qc.DefaultDatasetID = qq.DefaultDataset.DatasetId
if qq.MaximumBillingTier != nil {
qc.MaxBillingTier = int(*qq.MaximumBillingTier)
if qq.UseQueryCache != nil && !*qq.UseQueryCache {
qc.DisableQueryCache = true
if qq.FlattenResults != nil && !*qq.FlattenResults {
qc.DisableFlattenedResults = true
if qq.DestinationTable != nil {
qc.Dst = bqToTable(qq.DestinationTable, c)
for _, qp := range qq.QueryParameters {
p, err := bqToQueryParameter(qp)
if err != nil {
return nil, err
qc.Parameters = append(qc.Parameters, p)
return qc, nil
// QueryPriority specifies a priority with which a query is to be executed.
type QueryPriority string
const (
// BatchPriority specifies that the query should be scheduled with the
// batch priority. BigQuery queues each batch query on your behalf, and
// starts the query as soon as idle resources are available, usually within
// a few minutes. If BigQuery hasn't started the query within 24 hours,
// BigQuery changes the job priority to interactive. Batch queries don't
// count towards your concurrent rate limit, which can make it easier to
// start many queries at once.
// More information can be found at
BatchPriority QueryPriority = "BATCH"
// InteractivePriority specifies that the query should be scheduled with
// interactive priority, which means that the query is executed as soon as
// possible. Interactive queries count towards your concurrent rate limit
// and your daily limit. It is the default priority with which queries get
// executed.
// More information can be found at
InteractivePriority QueryPriority = "INTERACTIVE"
// A Query queries data from a BigQuery table. Use Client.Query to create a Query.
type Query struct {
client *Client
// Query creates a query with string q.
// The returned Query may optionally be further configured before its Run method is called.
func (c *Client) Query(q string) *Query {
return &Query{
client: c,
QueryConfig: QueryConfig{Q: q},
// Run initiates a query job.
func (q *Query) Run(ctx context.Context) (j *Job, err error) {
ctx = trace.StartSpan(ctx, "")
defer func() { trace.EndSpan(ctx, err) }()
job, err := q.newJob()
if err != nil {
return nil, err
j, err = q.client.insertJob(ctx, job, nil)
if err != nil {
return nil, err
return j, nil
func (q *Query) newJob() (*bq.Job, error) {
config, err := q.QueryConfig.toBQ()
if err != nil {
return nil, err
return &bq.Job{
JobReference: q.JobIDConfig.createJobRef(q.client),
Configuration: config,
}, nil
// Read submits a query for execution and returns the results via a RowIterator.
// If the request can be satisfied by running using the optimized query path, it
// is used in place of the jobs.insert path as this path does not expose a job
// object.
func (q *Query) Read(ctx context.Context) (it *RowIterator, err error) {
ctx = trace.StartSpan(ctx, "")
defer func() { trace.EndSpan(ctx, err) }()
queryRequest, err := q.probeFastPath()
if err != nil {
// Any error means we fallback to the older mechanism.
job, err := q.Run(ctx)
if err != nil {
return nil, err
return job.Read(ctx)
// we have a config, run on fastPath.
resp, err := q.client.runQuery(ctx, queryRequest)
if err != nil {
return nil, err
// construct a minimal job for backing the row iterator.
minimalJob := &Job{
c: q.client,
jobID: resp.JobReference.JobId,
location: resp.JobReference.Location,
projectID: resp.JobReference.ProjectId,
if resp.JobComplete {
rowSource := &rowSource{
j: minimalJob,
// RowIterator can precache results from the iterator to save a lookup.
cachedRows: resp.Rows,
cachedSchema: resp.Schema,
cachedNextToken: resp.PageToken,
return newRowIterator(ctx, rowSource, fetchPage), nil
// We're on the fastPath, but we need to poll because the job is incomplete.
// Fallback to job-based Read().
// (Issue 2937) In order to satisfy basic probing of the job in classic path,
// we need to supply additional config which is probed for presence, not contents.
minimalJob.config = &bq.JobConfiguration{
Query: &bq.JobConfigurationQuery{},
return minimalJob.Read(ctx)
// probeFastPath is used to attempt configuring a jobs.Query request based on a
// user's Query configuration. If all the options set on the job are supported on the
// faster query path, this method returns a QueryRequest suitable for execution.
func (q *Query) probeFastPath() (*bq.QueryRequest, error) {
// This is a denylist of settings which prevent us from composing an equivalent
// bq.QueryRequest due to differences between configuration parameters accepted
// by jobs.insert vs jobs.query.
if q.QueryConfig.Dst != nil ||
q.QueryConfig.TableDefinitions != nil ||
q.QueryConfig.CreateDisposition != "" ||
q.QueryConfig.WriteDisposition != "" ||
!(q.QueryConfig.Priority == "" || q.QueryConfig.Priority == InteractivePriority) ||
q.QueryConfig.UseLegacySQL ||
q.QueryConfig.MaxBillingTier != 0 ||
q.QueryConfig.TimePartitioning != nil ||
q.QueryConfig.RangePartitioning != nil ||
q.QueryConfig.Clustering != nil ||
q.QueryConfig.DestinationEncryptionConfig != nil ||
q.QueryConfig.SchemaUpdateOptions != nil ||
// User has defined the jobID generation behavior
q.JobIDConfig.JobID != "" {
return nil, fmt.Errorf("QueryConfig incompatible with fastPath")
pfalse := false
qRequest := &bq.QueryRequest{
Query: q.QueryConfig.Q,
Location: q.Location,
UseLegacySql: &pfalse,
MaximumBytesBilled: q.QueryConfig.MaxBytesBilled,
RequestId: uid.NewSpace("request", nil).New(),
Labels: q.Labels,
if q.QueryConfig.DisableQueryCache {
qRequest.UseQueryCache = &pfalse
// Convert query parameters
for _, p := range q.QueryConfig.Parameters {
qp, err := p.toBQ()
if err != nil {
return nil, err
qRequest.QueryParameters = append(qRequest.QueryParameters, qp)
if q.QueryConfig.DefaultDatasetID != "" {
qRequest.DefaultDataset = &bq.DatasetReference{
ProjectId: q.QueryConfig.DefaultProjectID,
DatasetId: q.QueryConfig.DefaultDatasetID,
return qRequest, nil