Please use the form below to provide your feedback. Because your feedback is valuable to us, the information you submit in this form is recorded in our issue tracking system (JIRA), which is publicly available. You can track the status of your feedback using the ticket number displayed in the dialog once you submit the form.

Query Service REST API

  • reference

Overview

The Query Service REST API is provided by the Query service. This API enables you to run SQL++ queries and set request-level parameters.

Version information

Version: 8.0

Host information

{scheme}://{host}:{port}

The URL scheme, host, and port are as follows.

Component Description

scheme

The URL scheme. Use https for secure access.

Values: http, https

host

The host name or IP address of a node running the Query Service.

Example: localhost

port

The Query Service REST port. Use 18093 for secure access.

Values: 8093, 18093

Examples on this page

In the HTTP request examples:

  • $BASEPATH is the URL scheme, host, and port for a node running the Query Service.

  • $USER is the user name of an authorized user — see Security.

  • $PASSWORD is the password to connect to Couchbase Server.

Resources

This section describes the operations available with this REST API.

Read-Only Query Service
Query Service

Read-Only Query Service

GET /query/service

Description

Enables you to execute a SQL++ statement. This method allows you to run SELECT queries, and specify query parameters.

This endpoint is intended for situations where use of the POST method is restricted.

Produces

  • application/json

Parameters

Query Parameters

Name Description Schema

body
required

Specify the parameters in the query URL in URL-encoded format. The format for URL-encoded parameters is consistent with the syntax for variables according to RFC 6570.

Request Parameters

Responses

This section describes the response HTTP status codes.

HTTP Code Description Schema

200

The operation was successful.

Response Body

400

Bad Request. The request cannot be processed for one of the following reasons: the statement contains a SQL++ syntax error; the request has a missing or unrecognized HTTP parameter; the request is badly formatted — for example, the request body contains a JSON syntax error.

Response Body

401

Unauthorized. The credentials provided with the request are missing or invalid.

403

Forbidden. There is a read-only violation. Either there was an attempt to create or update in a GET request or a POST request where readonly is set, or the client does not have the authorization to modify an object (index, keyspace or namespace) in the statement.

404

Not found. The statement in the request references an invalid namespace or keyspace.

Response Body

405

Method not allowed. The statement in the request references an invalid namespace or keyspace.

409

Conflict. There is an attempt to create an object (keyspace or index) that already exists.

410

Gone. The server is shutting down gracefully. Previously made requests are being completed, but no new requests are being accepted.

413

Payload too large. The query is too large for the Query Service to process.

500

Internal server error. There was an unforeseen problem processing the request.

503

Service unavailable. There is an issue (that is possibly temporary) preventing the request being processed; the request queue is full or the data store is not accessible.

Response Body

Security

Type Name

http (basic)

Header

apiKey

Parameter

Example HTTP Request

GET request with query parameters

curl request
curl -v $BASEPATH/query/service?statement=SELECT%20name%20FROM%20%60travel-sample%60.inventory.hotel%20LIMIT%201%3B \
     -u $USER:$PASSWORD

For more examples, see Examples.

Example HTTP Response

Response 200
{
  "requestID" : "615e0b26-dd61-4a1a-bda9-22333193b982",
  "signature" : {
    "name" : "json"
  },
  "results" : [ {
    "name" : "Medway Youth Hostel"
  } ],
  "status" : "success",
  "metrics" : {
    "elapsedTime" : "5.232754ms",
    "executionTime" : "5.160022ms",
    "resultCount" : 1,
    "resultSize" : 30,
    "serviceLoad" : 12
  }
}
Response 400
SQL++ Error
{
  "requestID" : "27087759-07af-431d-a3d7-29080f870e56",
  "errors" : [ {
    "code" : 3000,
    "msg" : "syntax error - line 1, column 7, near 'SLECT', at: name"
  } ],
  "status" : "fatal",
  "metrics" : {
    "elapsedTime" : "1.478631ms",
    "executionTime" : "1.393274ms",
    "resultCount" : 0,
    "resultSize" : 0,
    "serviceLoad" : 12,
    "errorCount" : 1
  }
}
Request Error
{
  "requestID" : "424c0a6d-b851-4feb-892c-0d9a106f2e13",
  "errors" : [ {
    "code" : 1050,
    "msg" : "No statement or prepared value"
  } ],
  "status" : "fatal",
  "metrics" : {
    "elapsedTime" : "1.124637ms",
    "executionTime" : "1.094663ms",
    "resultCount" : 0,
    "resultSize" : 0,
    "serviceLoad" : 0,
    "errorCount" : 1
  }
}
Response 404
{
  "requestID" : "d30b805f-6c1e-44ec-9aec-35ff711a6e88",
  "errors" : [ {
    "code" : 12003,
    "msg" : "Keyspace not found in CB datastore: default:travel-sample.inventory.motel"
  } ],
  "status" : "fatal",
  "metrics" : {
    "elapsedTime" : "3.096786ms",
    "executionTime" : "2.468282ms",
    "resultCount" : 0,
    "resultSize" : 0,
    "serviceLoad" : 12,
    "errorCount" : 1
  }
}
Response 503
{
  "requestID" : "5c0a6a81-2fc8-4a33-a035-ed7fb1512710",
  "errors" : [ {
    "code" : "<int>",
    "msg" : "Request queue full"
  } ],
  "status" : "errors",
  "metrics" : {
    "elapsedTime" : "134.7944us",
    "executionTime" : "130.5518us",
    "resultCount" : 0,
    "resultSize" : 0,
    "mutationCount" : 0,
    "errorCount" : 1,
    "warningCount" : 0
  }
}

Query Service

POST /query/service

Description

Enables you to execute a SQL++ statement. This method allows you to run SELECT queries and other DML statements, and specify query parameters.

Consumes

  • application/json

  • application/x-www-form-urlencoded

Produces

  • application/json

Parameters

For POST requests, you can specify form data parameters using the application/x-www-form-urlencoded MIME type. Alternatively, you can specify parameters in the request body using the application/json MIME type with the Content-Type header.

Body Parameter

Name Description Schema

Body
required

An object specifying one or more query parameters.

Request Parameters

Responses

This section describes the response HTTP status codes.

HTTP Code Description Schema

200

The operation was successful.

Response Body

400

Bad Request. The request cannot be processed for one of the following reasons: the statement contains a SQL++ syntax error; the request has a missing or unrecognized HTTP parameter; the request is badly formatted — for example, the request body contains a JSON syntax error.

Response Body

401

Unauthorized. The credentials provided with the request are missing or invalid.

403

Forbidden. There is a read-only violation. Either there was an attempt to create or update in a GET request or a POST request where readonly is set, or the client does not have the authorization to modify an object (index, keyspace or namespace) in the statement.

404

Not found. The statement in the request references an invalid namespace or keyspace.

Response Body

405

Method not allowed. The statement in the request references an invalid namespace or keyspace.

409

Conflict. There is an attempt to create an object (keyspace or index) that already exists.

410

Gone. The server is shutting down gracefully. Previously made requests are being completed, but no new requests are being accepted.

413

Payload too large. The query is too large for the Query Service to process.

500

Internal server error. There was an unforeseen problem processing the request.

503

Service unavailable. There is an issue (that is possibly temporary) preventing the request being processed; the request queue is full or the data store is not accessible.

Response Body

Security

Type Name

http (basic)

Header

apiKey

Parameter

Example HTTP Request

POST request with parameters as form data

curl request
curl -v $BASEPATH/query/service \
     -d 'statement=SELECT name FROM `travel-sample`.inventory.hotel LIMIT 1' \
     -u $USER:$PASSWORD

Because it’s sent as form data, the statement in this example avoids using a semicolon.

POST request with parameters in JSON format

curl request
curl -v $BASEPATH/query/service \
     -H 'Content-Type: application/json' \
     -d '{ "statement": "SELECT name FROM `travel-sample`.inventory.hotel LIMIT 1;" }' \
     -u $USER:$PASSWORD

Conversely, because it’s sent as a JSON object, the statement in this example can contain a semicolon.

For more examples, see Examples.

Example HTTP Response

Response 200
{
  "requestID" : "615e0b26-dd61-4a1a-bda9-22333193b982",
  "signature" : {
    "name" : "json"
  },
  "results" : [ {
    "name" : "Medway Youth Hostel"
  } ],
  "status" : "success",
  "metrics" : {
    "elapsedTime" : "5.232754ms",
    "executionTime" : "5.160022ms",
    "resultCount" : 1,
    "resultSize" : 30,
    "serviceLoad" : 12
  }
}
Response 400
SQL++ Error
{
  "requestID" : "27087759-07af-431d-a3d7-29080f870e56",
  "errors" : [ {
    "code" : 3000,
    "msg" : "syntax error - line 1, column 7, near 'SLECT', at: name"
  } ],
  "status" : "fatal",
  "metrics" : {
    "elapsedTime" : "1.478631ms",
    "executionTime" : "1.393274ms",
    "resultCount" : 0,
    "resultSize" : 0,
    "serviceLoad" : 12,
    "errorCount" : 1
  }
}
Request Error
{
  "requestID" : "424c0a6d-b851-4feb-892c-0d9a106f2e13",
  "errors" : [ {
    "code" : 1050,
    "msg" : "No statement or prepared value"
  } ],
  "status" : "fatal",
  "metrics" : {
    "elapsedTime" : "1.124637ms",
    "executionTime" : "1.094663ms",
    "resultCount" : 0,
    "resultSize" : 0,
    "serviceLoad" : 0,
    "errorCount" : 1
  }
}
Response 404
{
  "requestID" : "d30b805f-6c1e-44ec-9aec-35ff711a6e88",
  "errors" : [ {
    "code" : 12003,
    "msg" : "Keyspace not found in CB datastore: default:travel-sample.inventory.motel"
  } ],
  "status" : "fatal",
  "metrics" : {
    "elapsedTime" : "3.096786ms",
    "executionTime" : "2.468282ms",
    "resultCount" : 0,
    "resultSize" : 0,
    "serviceLoad" : 12,
    "errorCount" : 1
  }
}
Response 503
{
  "requestID" : "5c0a6a81-2fc8-4a33-a035-ed7fb1512710",
  "errors" : [ {
    "code" : "<int>",
    "msg" : "Request queue full"
  } ],
  "status" : "errors",
  "metrics" : {
    "elapsedTime" : "134.7944us",
    "executionTime" : "130.5518us",
    "resultCount" : 0,
    "resultSize" : 0,
    "mutationCount" : 0,
    "errorCount" : 1,
    "warningCount" : 0
  }
}

Definitions

This section describes the properties consumed and returned by this REST API.

Conditions
Controls
Credentials
Execution Timings
Metrics
Profile
Request Parameters
Response Body
Statistics

Conditions

Object

Property Schema

code
required

A unique number that identifies the error or warning. The code ranges are partitioned by component. The codes can also include parts that indicate severity and transience. This property is always present in every condition returned in the Query REST API or captured in a log.

Integer

msg
required

A message describing the error or warning in detail. This property is always present in every condition returned in the Query REST API or captured in a log.

String

name
optional

Unique name that has a 1:1 mapping to the code. Uniquely identifies the condition. This property is helpful for pattern matching and can have meaning, making it more memorable than the code. The name should be fully qualified.

Example: "indexing.scan.io_failure"

String

sev
optional

One of the following SQL++ severity levels, listed in order of severity:

  1. Severe
  2. Error
  3. Warn
  4. Info

Integer

temp
optional

Indicates if the condition is transient — for example, the queue is full. If the value is false, it tells clients and users that a retry without modification produces the same condition.

Boolean

Additional elements not listed here might also be present. Clients and consumers of the REST API or the logs must accommodate any additional elements.

Controls

Object

Property Schema

scan_consistency
optional

The value of the query setting Scan Consistency used for the query.

String

use_cbo
optional

Whether the cost-based optimizer was enabled for the query.

Boolean

memoryQuota
optional

The memory quota for the request, in MB. This property is only returned if a memory quota was set for the query.

Integer (unsigned)

stmtType
optional

The type of query statement.

Example: "SELECT"

String

Additional elements not listed here might also be present. Clients and consumers of the REST API or the logs must accommodate any additional elements.

Credentials

Object

Property Schema

user
optional

An identity for authentication. Note that bucket names may be prefixed with local:, and admin names may be prefixed with admin:.

Example: "local:bucket-name"

String

pass
optional

A password for authentication.

Example: "password"

String

Execution Timings

Object

Property Schema

#operator
required

Name of the operator.

Example: "Fetch"

String

#stats
required

Statistics collected for the operator.

Statistics

~child
optional

Further nested operators, each with their own execution timings.

Object

Metrics

Object

Property Schema

elapsedTime
required

The total time taken for the request, that is the time from when the request was received until the results were returned.

String (duration)

executionTime
required

The time taken for the execution of the request, that is the time from when query execution started until the results were returned.

String (duration)

resultCount
required

The total number of objects in the results.

Integer (unsigned)

resultSize
required

The total number of bytes in the results.

Integer (unsigned)

naturalLanguageProcessingTime
optional

The total time spent processing a natural language request. The cumulation of authentication, collecting schema, and time waiting for the response from the LLM, or wait time for the natural language request to be serviced.

String (duration)

mutationCount
optional

The number of mutations that were made during the request.

Integer (unsigned)

sortCount
optional

The number of objects that were sorted. Present only if the request includes ORDER BY.

If a query includes ORDER BY, LIMIT, or OFFSET clauses, an application can use the sortCount value to give the overall number of results in a message such as "page 1 of N".

Integer (unsigned)

usedMemory
optional

The amount of document memory used to execute the request. This property is only returned if a memory quota was set for the query.

Integer (unsigned)

errorCount
optional

The number of errors that occurred during the request.

Integer (unsigned)

warningCount
optional

The number of warnings that occurred during the request.

Integer (unsigned)

sessionMemory
optional

The memory session size for the request, in bytes.

Each request has a dedicated memory session. When a query requires a document or value, memory is allocated from this session based on the size of the document or value. Once the document or value is processed, the allocated memory is returned back to the session, enabling it to be reused by the request.

This metric is available only when node-quota and node-quota-val-percent are configured for the node.

Integer (bytes)

Additional elements not listed here might also be present. Clients and consumers of the REST API or the logs must accommodate any additional elements.

Profile

Object

Property Schema

requestTime
required

Timestamp when the query was received.

Date (date-time)

servicingHost
required

IP address and port number of the node where the query was executed.

String

phaseCounts
required

Count of documents processed at selective phases involved in the query execution, such as authorize, index scan, fetch, parse, plan, run, etc.

Example: {"fetch":16,"indexScan":187}

Object

phaseOperators
required

Indicates the numbers of each kind of query operator involved in different phases of the query processing.

For instance, a non-covering index path might involve one index scan and one fetch operator. A join would probably involve two or more fetches, one per keyspace. A union select would have twice as many operator counts, one per each branch of the union.

This is in essence the count of all the operators in the executionTimings object.

Example: {"authorize":1,"fetch":1,"indexScan":2}

Object

phaseTimes
required

Cumulative execution times for various phases involved in the query execution, such as authorize, index scan, fetch, parse, plan, run, etc.

Example: {"authorize":"823.631µs","fetch":"656.873µs","indexScan":"29.146543ms","instantiate":"236.221µs","parse":"826.382µs","plan":"11.831101ms","run":"16.892181ms"}

Object

executionTimings
optional

Present only if profile was set to "timings" in the request parameters.

The execution details for various phases involved in the query execution, such as kernel and service execution times, number of documents processed at each query operator in each phase, and number of phase switches.

Execution Timings

ioTime
optional

The total sum of servTime across all operators.

Example: "752.858519ms"

String (duration)

waitTime
optional

The total sum of kernTime across all operators.

Example: "1.201307s"

String (duration)

cpuTime
optional

The total sum of execTime across all operators.

Example: "90.734075ms"

String (duration)

~analysis
optional

An array of text phrases that provide a basic analysis of the request execution. These phrases highlight notable aspects of the execution, such as high document counts during primary scans or warnings related to memory and resource usages.

Example: ["High IO time","High primary scan document count"]

String array

Request Parameters

Object

Property Schema

args
optional

Supplies the values for positional parameters in the statement. Applicable if the statement or prepared statement contains 1 or more positional parameters.

The value is an array of JSON values, one for each positional parameter in the statement.

Refer to Named Parameters and Positional Parameters for details.

Example: ["LAX",6]

Any Type array

atrcollection
optional

Specifies the collection where the active transaction record (ATR) is stored. The collection must be present. If not specified, the ATR is stored in the default collection in the default scope in the bucket containing the first mutated document within the transaction.

The value must be a string in the form "bucket.scope.collection" or "namespace:bucket.scope.collection". If any part of the path contains a special character, that part of the path must be delimited in backticks ``.

The node-level atrcollection setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting.

Example: "default:`travel-sample`.transaction.test"

String

auto_execute
optional

Specifies that prepared statements should be executed automatically as soon as they are created. This saves you from having to make two separate requests in cases where you want to prepare a statement and execute it immediately.

Refer to Auto-Execute for more information.

Default: false
Example: true

Boolean

client_context_id
optional

A piece of data supplied by the client that is echoed in the response, if present. SQL++ is agnostic about the content of this parameter; it is just echoed in the response.

  • Maximum allowed size is 64 characters; all others will be cut.
  • If it contains an escape character / or quote ", it will be rejected as error code 1110.

String

compression
optional

Compression format to use for response data on the wire.

Values are case-insensitive.

Values: "ZIP", "RLE", "LZMA", "LZO", "NONE"
Default: "NONE"
Example: "zip"

String

controls
optional

Specifies if there should be a controls section returned with the request results.

When set to true, the query response document includes a controls section with runtime information provided along with the request, such as positional and named parameters or settings.

If the request qualifies for caching, these values will also be cached in the completed_requests system keyspace.

The node-level controls setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting.

Example: true

Boolean

creds
optional

Specifies the login credentials. The Query API supports two types of identity: local (or bucket) and admin.

The format is an identity and password. You can specify credentials for multiple identities.

If credentials are supplied in the request header, then HTTP Basic Authentication takes precedence and creds is ignored.

Example: [{"user":"local:bucket-name","pass":"password"},{"user":"admin:admin-name","pass":"password"}]

Credentials array

durability_level
optional

The level of durability for mutations produced by the request.

If the request contains a BEGIN TRANSACTION statement, or a DML statement with the tximplicit parameter set to true, the durability level is specified for all mutations within that transaction.

Durability is also supported for non-transactional DML statements. In this case, the kvtimeout parameter is used as the durability timeout.

If not specified, the default durability level is "majority". Set the durability level to "none" or "" to specify no durability.

Values: "", "none", "majority", "majorityAndPersistActive", "persistToMajority"
Default: "majority"
Example: "none"

String

encoded_plan
optional

In clusters running Couchbase Server 6.5 and later, this parameter is ignored and has no effect. It is included for compatibility with previous versions.

String

encoding
optional

Desired character encoding for the query results.

Only possible value is UTF-8 and is case-insensitive.

Default: "UTF-8"

String

format
optional

Desired format for the query results.

Values are case-insensitive.

Values: "JSON", "XML", "CSV", "TSV"
Default: "JSON"
Example: "XML"

String

kvtimeout
optional

The approximate time to wait for a KV get operation before timing out. This applies to statements within a transaction, and to non-transactional statements, whether durability_level is set or not.

If use_replica is enabled for a query, then this parameter also specifies the approximate time to wait before fetching data from a replica vBucket when the active vBucket is inaccessible.

The value for this parameter is a string. Its format includes an amount and a mandatory unit, e.g. 10ms (10 milliseconds) or 0.5s (half a second). Valid units are:

  • ns (nanoseconds)
  • us (microseconds)
  • ms (milliseconds)
  • s (seconds)
  • m (minutes)
  • h (hours)

Specify a duration of 0 or a negative duration to disable. When disabled, no timeout is applied and the KV operation runs for however long it takes.

Default: "2.5s"
Example: "10ms"

String

max_parallelism
optional

Specifies the maximum parallelism for the query.

The default value is the same as the number of partitions of the index selected for the query.

The node-level max-parallelism setting specifies the ceiling for this parameter for a single node. If the request-level parameter is zero or negative, the parallelism for the query is set to the node-level setting. If the request-level parameter is greater than zero and less than the node-level setting, the request-level parameter overrides the node-level setting. If the request-level parameter is greater than the node-level setting, the parallelism for the query is set to the node-level setting.

In addition, the cluster-level queryMaxParallelism setting specifies the ceiling for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

To enable queries to run in parallel, you must specify the cluster-level queryMaxParallelism parameter, or specify the node-level max-parallelism parameter on all Query nodes.

Example: 3

Integer (int32)

memory_quota
optional

Specifies the maximum amount of memory the request may use, in MB.

Specify 0 (the default value) to disable. When disabled, there is no quota.

This parameter enforces a ceiling on the memory used for the tracked documents required for processing a request. It does not take into account any other memory that might be used to process a request, such as the stack, the operators, or some intermediate values.

Within a transaction, this setting enforces the memory quota for the transaction by tracking the delta table and the transaction log (approximately).

The node-level memory-quota setting specifies the ceiling for this parameter for a single node. If the node-level setting is zero (the default), the request-level parameter overrides the node-level setting. If the node-level setting is greater than zero, the request-level parameter is capped by the node-level setting.

In addition, the cluster-level queryMemoryQuota setting specifies the ceiling for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Default: 0
Example: 4

Integer (int32)

metrics
optional

Specifies that metrics should be returned with query results.

Default: true
Example: false

Boolean

namespace
optional

Specifies the namespace to use. Currently, only the default namespace is available.

Example: "default"

String

natural
optional

Couchbase Server 8.0

The prompt for a natural language request. The Query Service uses the prompt to generate a SQL++ statement.

If the generated statement is a SELECT statement, the generated statement is returned and executed automatically.

If the generated statement is not a SELECT statement, the generated statement is returned, but not executed. In this case, you must verify the statement and execute it in a separate request.

Natural language requests use the Couchbase Capella iQ service as a backend. To make a natural language request, you must have a Couchbase Capella user account.

This parameter is available in clusters running Couchbase Server 8.0 and later.

To use this parameter, you must also specify the natural_cred, natural_orgid, and natural_context parameters. If you don't specify all four parameters, the Query Service returns an error.

Example: "Show me count of airlines per country"

String

natural_cred
optional

Couchbase Server 8.0

The Couchbase Capella user account credentials for a natural language request, in the form username:password. Be careful not to expose the credentials in log files or other output.

This parameter does not support single sign-on (SSO), multi-factor authentication (MFA), or social login credentials such as Google or GitHub.

Natural language requests use the Couchbase Capella iQ service as a backend. To make a natural language request, you must have a Couchbase Capella user account.

This parameter is available in clusters running Couchbase Server 8.0 and later.

To use this parameter, you must also specify the natural, natural_orgid, and natural_context parameters. If you don't specify all four parameters, the Query Service returns an error.

Example: "username:password"

String (password)

natural_orgid
optional

Couchbase Server 8.0

The Couchbase Capella organization ID for a natural language request.

Natural language requests use the Couchbase Capella iQ service as a backend. To make a natural language request, you must have a Couchbase Capella user account.

This parameter is available in clusters running Couchbase Server 8.0 and later.

To use this parameter, you must also specify the natural, natural_cred, and natural_context parameters. If you don't specify all four parameters, the Query Service returns an error.

UUID (uuid)

natural_context
optional

Couchbase Server 8.0

A list of paths specifying keyspaces for a natural language request. The Query Service infers the schema of each keyspace, in order to give more precise responses from the natural language request.

The parameter may contain up to four paths, separated by commas. Spaces are allowed. Each path may be:

  • A full path, in the form bucket.scope.collection or namespace:bucket.scope.collection.

  • A path prefix, in the form namespace:bucket or bucket, to specify the default collection in the default scope.

  • A partial path, in the form collection. In this case, you must specify the query_context parameter to provide the bucket and scope.

Natural language requests use the Couchbase Capella iQ service as a backend. To make a natural language request, you must have a Couchbase Capella user account.

This parameter is available in clusters running Couchbase Server 8.0 and later.

To use this parameter, you must also specify the natural, natural_cred, and natural_orgid parameters. If you don't specify all four parameters, the Query Service returns an error.

Example: "travel-sample, travel-sample.inventory.airline, airline"

String

natural_output
optional

Couchbase Server 8.0

Specifies the required output for a natural language request.

  • sql — The output is a SQL++ statement.

  • jsudf — The output is a CREATE FUNCTION statement which you can use to generate a SQL++ managed JavaScript user-defined function.

  • ftssql — The output is a SQL++ statement which can use a Flex index, if available.

Natural language requests use the Couchbase Capella iQ service as a backend. To make a natural language request, you must have a Couchbase Capella user account.

This parameter is available in clusters running Couchbase Server 8.0 and later.

Values: "sql", "jsudf", "ftssql"
Default: "sql"

String

numatrs
optional

Reserved for future use. This parameter is ignored and has no effect.

Integer (int32)

pipeline_batch
optional

Controls the number of items execution operators can batch for Fetch from the KV.

The node-level pipeline-batch setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting, but only if it is lower than the node-level setting.

In addition, the cluster-level queryPipelineBatch setting specifies the default for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Example: 64

Integer (int32)

pipeline_cap
optional

Maximum number of items each execution operator can buffer between various operators.

The node-level pipeline-cap setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting, but only if it is lower than the node-level setting.

In addition, the cluster-level queryPipelineCap setting specifies the default for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Example: 1024

Integer (int32)

prepared
optional

Required if statement or natural not provided.

The name of the prepared SQL++ statement to be executed. Refer to EXECUTE for examples.

If both prepared and statement are present and non-empty, an error is returned.

Example: "[127.0.0.1:8091]pricy_hotel"

String

preserve_expiry
optional

Specifies whether documents should keep their current expiration setting when modified by a DML statement.

If true, documents will keep any existing expiration setting when modified by a DML statement. If the DML statement explicitly specifies the document expiration, the statement overrides this parameter, and the expiration is changed.

If false, document expiration is set to 0 when modified by a DML statement, unless the DML statement explicitly specifies the document expiration.

Not supported for statements in a transaction.

Default: false
Example: true

Boolean

pretty
optional

Specifies the query results returned in pretty format.

The node-level pretty setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting.

Example: false

Boolean

profile
optional

Specifies if there should be a profile section returned with the request results. The valid values are:

  • off — No profiling information is added to the query response.

  • phases — The query response includes a profile section with stats and details about various phases of the query plan and execution. Three phase times will be included in the system:active_requests and system:completed_requests monitoring keyspaces.

  • timings — Besides the phase times, the profile section of the query response document will include a full query plan with timing and information about the number of processed documents at each phase. This information will be included in the system:active_requests and system:completed_requests keyspaces.

If profile is not set as one of the above values, then the profile setting does not change.

The node-level profile setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting.

Values: "off", "phases", "timings"
Example: "phases"

String

query_context
optional

Specifies the namespace, bucket, and scope used to resolve partial keyspace references within the request.

The query context may be a full path, containing namespace, bucket, and scope; or a relative path, containing just the bucket and scope. Currently, only the default namespace is available. If the namespace name is omitted, the default namespace in the current session is used.

Default: "default:"
Example: "default:travel-sample.inventory"

String

readonly
optional

Controls whether a query can change a resulting recordset.

If readonly is true, then the following statements are not allowed:

  • CREATE INDEX
  • DROP INDEX
  • INSERT
  • MERGE
  • UPDATE
  • UPSERT

When using GET requests, it's best to set readonly to true.

Default: false
Example: true

Boolean

scan_cap
optional

Maximum buffered channel size between the indexer client and the query service for index scans. This parameter controls when to use scan backfill.

Use 0 or a negative number to disable. Smaller values reduce GC, while larger values reduce indexer backfill.

The node-level scan-cap setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting, but only if it is lower than the node-level setting.

In addition, the cluster-level queryScanCap setting specifies the default for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Example: 1024

Integer (int32)

scan_consistency
optional

Specifies the consistency guarantee or constraint for index scanning. The valid values are:

  • not_bounded — No timestamp vector is used in the index scan. This is the fastest mode, because it avoids the costs of obtaining the vector and waiting for the index to catch up to the vector.

  • at_plus — This implements bounded consistency. The request includes a scan_vector parameter and value, which is used as a lower bound. This can be used to implement read-your-own-writes (RYOW).

  • request_plus — This implements strong consistency per request. Before processing the request, a current vector is obtained. The vector is used as a lower bound for the statements in the request. If there are DML statements in the request, RYOW is also applied within the request. (If request_plus is specified in a query that runs during a failover of an index node, the query waits until the rebalance operation completes and the index data has rebalanced before returning a result.)

  • statement_plus — This implements strong consistency per statement. Before processing each statement, a current vector is obtained and used as a lower bound for that statement.

Values are case-insensitive.

For multi-statement requests, the default behavior is RYOW within each request. If you want to disable RYOW within a request, add a separate request_consistency parameter that can be set to not_bounded.

If the request contains a BEGIN TRANSACTION statement, or a DML statement with the tximplicit parameter set to true, then this parameter sets the transactional scan consistency. Refer to Transactional Scan Consistency for details.

Values: "not_bounded", "at_plus", "request_plus", "statement_plus"
Default: "not_bounded"
Example: "at_plus"

String

scan_vector
optional

Required if scan_consistency is at_plus and scan_vectors not provided.

Specify the lower bound vector timestamp for one keyspace when using at_plus scan consistency.

Scan vectors are built of two-element [value, guard] entries:

  • value: a vBucket's sequence number (a JSON number)
  • guard: a vBucket's UUID (a string)

Scan vectors have two forms:

  1. Full: an array of [value, guard] entries, giving an entry for every vBucket in the system.
  2. Sparse: an object providing entries for specific vBuckets, mapping a vBucket number (a string) to each [value, guard] entry.

Note that scan_vector can only be used if the query uses at most one keyspace; if it is used for a query referencing more than one keyspace, the query will fail with an error.

For queries referencing multiple keyspaces, use scan_vectors.

Example: {"5":[5409393,"VB5ID"],"19":[47574574,"VB19ID"]}

Object

scan_vectors
optional

Required if scan_consistency is at_plus and scan_vector not provided.

A map from keyspace names to scan vectors. See scan_vector.

The scan vectors can be Full or Sparse.

Object

scan_wait
optional

Can be supplied with scan_consistency values of request_plus, statement_plus and at_plus.

Specifies the maximum time the client is willing to wait for an index to catch up to the vector timestamp in the request.

Specifies how much time the client is willing to wait for the indexer to satisfy the required scan_consistency and scan_vector criteria. After receiving the scan request, if the indexer is unable to catch up within the scan_wait time and initiate the scan, the indexer aborts with an error and the scan fails.

Its format includes an amount and a mandatory unit, e.g. 10ms (10 milliseconds) or 0.5s (half a second). Valid units are:

  • ns (nanoseconds)
  • us (microseconds)
  • ms (milliseconds)
  • s (seconds)
  • m (minutes)
  • h (hours)

Specify 0 or a negative integer to disable.

Default: ""
Example: "30m"

String (duration)

signature
optional

Include a header for the results schema in the response.

Default: true
Example: false

Boolean

sort_projection
optional

If true, causes statement projection terms to be sorted alphabetically.

If false (the default), statement projection terms are returned in the order specified by the query.

Default: false
Example: true

Boolean

statement
optional

Required if prepared or natural not provided.

Any valid SQL++ statement for a POST request, or a read-only SQL++ statement (SELECT, EXPLAIN) for a GET request.

If both prepared and statement are present and non-empty, an error is returned.

When specifying the request parameters as form data, the statement may not contain an unescaped semicolon (;). If it does, the Query Service responds with error 1040. To avoid this, either URL-encode the semicolon as %3B, or just omit the semicolon if possible.

This restriction does not apply when specifying the request parameters in JSON format.

Example: "SELECT * FROM `travel-sample`.inventory.hotel LIMIT 1"

String

timeout
optional

Maximum time to spend on the request before timing out (s).

The value for this parameter is a string. Its format includes an amount and an optional unit: for example, 10ms (10 milliseconds) or 0.5s (half a second). If not specified, the default unit is s (seconds). Valid units are:

  • ns (nanoseconds)
  • us (microseconds)
  • ms (milliseconds)
  • s (seconds)
  • m (minutes)
  • h (hours)

Specify a duration of 0 or a negative duration to disable. When disabled, no timeout is applied and the request runs for however long it takes.

If tximplicit or txid is set, this parameter is ignored. The request inherits the remaining time of the transaction as timeout.

The node-level timeout setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting. However, if the node-level setting is greater than 0, the timeout for the query is limited to the node-level setting.

In addition, the cluster-level queryTimeout setting specifies the default for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Example: "30m"

String (duration)

txdata
optional

Transaction data. For internal use only.

Object

txid
optional

Required for statements within a transaction.

Transaction ID. Specifies the transaction to which a statement belongs. For use with DML statements within a transaction, rollbacks, and commits.

The transaction ID should be the same as the transaction ID generated by the BEGIN TRANSACTION statement. The transaction must be active and non-expired.

Example: "d81d9b4a-b758-4f98-b007-87ba262d3a51"

UUID (UUID)

tximplicit
optional

Specifies that a DML statement is a singleton transaction.

When this parameter is true, the Query service starts a transaction and executes the statement. If execution is successful, the Query service commits the transaction; otherwise the transaction is rolled back.

The statement may not be part of an ongoing transaction. If the txid request-level parameter is set, the tximplicit parameter is ignored.

Default: false
Example: true

Boolean

txstmtnum
optional

Transaction statement number. The transaction statement number must be a positive integer, and must be higher than any previous transaction statement numbers in the transaction. If the transaction statement number is lower than the transaction statement number for any previous statement, an error is generated.

Example: 10

Integer (int32)

txtimeout
optional

Maximum time to spend on a transaction before timing out. Only applies to BEGIN TRANSACTION statements, or DML statements for which tximplicit is set. For other statements, it is ignored.

Within a transaction, the request-level timeout parameter is ignored. The transaction timeout clock starts when the BEGIN WORK statement is successful. Once the transaction timeout is reached, no statement is allowed to continue in the transaction.

The value for this parameter is a string. Its format includes an amount and a mandatory unit, e.g. 10ms (10 milliseconds) or 0.5s (half a second). Valid units are:

  • ns (nanoseconds)
  • us (microseconds)
  • ms (milliseconds)
  • s (seconds)
  • m (minutes)
  • h (hours)

Specify a duration of 0 to disable. When disabled, the request-level timeout is set to the default.

The default is "15s" for cbq files or scripts, "2m" for interactive cbq sessions or redirected input.

The node-level txtimeout setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting. However, if the node-level setting is greater than 0, the transaction timeout for the query is limited to the node-level setting.

In addition, the cluster-level queryTxTimeout setting specifies the default for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Example: "30m"

String (duration)

use_cbo
optional

Specifies whether the cost-based optimizer is enabled.

The node-level use-cbo setting specifies the default for this parameter for a single node. The request-level parameter overrides the node-level setting.

In addition, the cluster-level queryUseCBO setting specifies the default for this parameter for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Example: true

Boolean

use_fts
optional

ENTERPRISE EDITION

Specifies that the query should use a Search index.

If the query contains a USING FTS hint, that takes priority over this parameter.

If the query does not contain a USING FTS hint, and this parameter is set to true, all Search indexes are considered for the query. If a qualified Search index is available, it is selected for the query. If none of the available Search indexes are qualified, the available GSI indexes are considered instead.

Refer to Flex Indexes for more information.

Default: false
Example: true

Boolean

use_replica
optional

Specifies whether a query can fetch data from a replica vBucket if active vBuckets are inaccessible. The possible values are:

  • off — read from replica is disabled for this request.

  • on — read from replica is enabled for this request, unless it has been disabled for all requests at node level.

  • unset — read from replica is specified by the node-level setting. If the node-level setting is also unset, read from replica is disabled for this request.

Do not enable read from replica when you require consistent results. Only SELECT queries that are not within a transaction can read from replica.

Reading from replica is only possible if the cluster uses Couchbase Server 7.6.0 or later.

Note that KV range scans cannot currently be started on a replica vBucket. If a query uses sequential scan and a data node becomes unavailable, the query might return an error, even if read from replica is enabled for the request.

The node-level use-replica setting specifies the default for this property for a single node. The request-level parameter usually overrides the node-level setting. However, when the node-level setting is off, the request-level parameter cannot enable the property.

In addition, the cluster-level queryUseReplica setting specifies the default for this property for the whole cluster. When you change the cluster-level setting, the node-level setting is overwritten for all nodes in the cluster.

Values: "off", "on", "unset"
Default: "unset"
Example: "on"

String

<$identifier>
additional
property

Supplies the value for a named parameter in the statement. Applicable if the statement or prepared statement contains 1 or more named parameters.

The name of this property consists of two parts:

  1. The $ character or the @ character.
  2. An identifier that specifies the name of the parameter. This starts with an optional underscore (_), followed by an alpha character, followed by one or more alphanumeric characters, and ends with an optional underscore (_).

If the named parameter contains sensitive information, start and end the name of the parameter (after the initial $ or @) with an underscore (_). This masks the parameter value in the active requests catalog, the completed requests catalog, the response controls section, the cbq shell file history, and the query logs. When masked, a string parameter value is replaced by asterisks (*); other parameter values are replaced by null. Parameter masking is available in clusters running Couchbase Server 7.6.8 and later.

The value of the named parameter can be any JSON value.

Refer to Named Parameters and Positional Parameters for details.

Nullable: yes
Example: LAX

Any Type

Response Body

Object

Property Schema

requestID
optional

A unique identifier for the response.

UUID (UUID)

clientContextID
optional

The client context ID of the request, if one was supplied — see client_context_id in the request parameters.

String

generated_statement
optional

Couchbase Server 8.0

The generated statement, if the request was a natural language prompt.

Example: "SELECT country, COUNT(*) AS `airline_count` FROM `travel-sample`.`inventory`.`airline` AS `a` GROUP BY country"

String

signature
optional

The schema of the results. Present only when the query completes successfully.

Example: {"id":"json"}

Object

results
optional

An array of all the objects returned by the query. An object can be any JSON value.

Any Type array

status
optional

The status of the request.

Values: "success", "running", "errors", "completed", "stopped", "timeout", "fatal"

String

errors
optional

An array of 0 or more error objects. If an error occurred during processing of the request, it will be represented by an error object in this list.

Conditions array

warnings
optional

An array of 0 or more warning objects. If a warning occurred during processing of the request, it is represented by a warning object in this list.

Conditions array

metrics
optional

An object containing metrics about the request.

Metrics

controls
optional

An object containing runtime information provided along with the request. Present only if controls was set to true in the request parameters.

Controls

profile
optional

An object containing monitoring and profiling information about the request. Present only if profile was set to "phases" or "timings" in the request parameters.

Profile

Statistics

Object

Property Schema

#itemsIn
optional

Number of input documents to the operator.

Example: 187

Integer (int32)

#itemsOut
optional

Number of output documents after the operator processing.

Example: 16

Integer (int32)

#phaseSwitches
optional

Number of switches between executing, waiting for services, or waiting for the goroutine scheduler.

Example: 413

Integer (int32)

execTime
optional

Time spent executing the operator code inside SQL++ query engine.

Example: "128.434µs"

String (duration)

kernTime
optional

Time spent waiting to be scheduled for CPU time.

Example: "15.027879ms"

String (duration)

servTime
optional

Time spent waiting for another service, such as index or data.

For index scan, it is time spent waiting for GSI/indexer.

For fetch, it is time spent waiting on the KV store.

Example: "1.590934ms"

String (duration)

The kernTime, servTime, and execTime statistics can be helpful in troubleshooting query performance issues. For example:

  • A high servTime for a low number of items processed is an indication that the indexer or KV store is stressed.

  • A high kernTime means there is a downstream issue in the query plan or the query server having many requests to process, so the scheduled waiting time will be more for CPU time.

Security

The Query Service API accepts credentials via HTTP basic authentication header, or via the creds request parameter. If a request contains both HTTP basic authentication header and a creds parameter, the creds parameter is ignored and only the HTTP basic authentication header is used for authenticating.

Header

Specify a user name and password via HTTP headers. This method can only be used to provide a single credential.

Type: http

Parameter

Specify user names and passwords via the creds request parameter. This is the only method that can provide multiple credentials for a request.

API Key

Key parameter: creds
Key in: query

RBAC Role

Users must have the relevant Administrative or Query & Index RBAC roles, depending on the types of query they intend to run. In addition, users must have permissions on the required buckets, scopes, and collections, where appropriate. For more information, see Roles.

See Also