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This page describes how to create a Dataplex Universal Catalog data quality scan.
To learn about data quality scans, seeAbout auto data quality.
Tip: The steps in this document show how to manage data quality scans acrossyour project. You can also create and manage data quality scans when workingwith a specific table. For more information, see theManage data quality scans for a specific table sectionof this document.Before you begin
Enable the Dataplex API.
Roles required to enable APIs
To enable APIs, you need the Service Usage Admin IAM role (
roles/serviceusage.serviceUsageAdmin), which contains theserviceusage.services.enablepermission.Learn how to grant roles.- Optional: If you want Dataplex Universal Catalog to generate recommendations fordata quality rules based on the results of a data profile scan,create and run the data profile scan.
Required roles
To run a data quality scan on a BigQuery table, you needpermission to read the BigQuery table and permission tocreate a BigQuery job in the project used to scan the table.
Note: Dataplex Universal Catalog doesn't create a BigQuery job inyour project. However, you need this permission to create aDryRunjob tocheck for permissions for the table.If the BigQuery table and the data quality scan are indifferent projects, then you need to give the Dataplex Universal Catalog serviceaccount of the project containing the data quality scan read permission forthe corresponding BigQuery table.
Note: If you haven't created any data quality or data profile scans or youdon't have a Dataplex Universal Catalog lake in this project, create aservice identifier by running:gcloud beta services identity create --service=dataplex.googleapis.com.This command returns a Dataplex Universal Catalog service identifier if it exists.If the data quality rules refer to additional tables, then the scan project'sservice account must have read permissions on the same tables.
To get the permissions that you need to export the scan results to aBigQuery table, ask your administrator to grant theDataplex Universal Catalog service account theBigQuery Data Editor (
roles/bigquery.dataEditor) IAM role on theresults dataset and table. This grants the following permissions:bigquery.datasets.getbigquery.tables.createbigquery.tables.getbigquery.tables.getDatabigquery.tables.updatebigquery.tables.updateData
If the BigQuery data is organized in a Dataplex Universal Cataloglake, grant the Dataplex Universal Catalog service account theDataplex Metadata Reader (
roles/dataplex.metadataReader) andDataplex Viewer (roles/dataplex.viewer) IAM roles.Alternatively, you need all of the following permissions:dataplex.lakes.listdataplex.lakes.getdataplex.zones.listdataplex.zones.getdataplex.entities.listdataplex.entities.getdataplex.operations.get
If you're scanning a BigQuery external table fromCloud Storage, grant the Dataplex Universal Catalog service account theStorage Object Viewer (
roles/storage.objectViewer) role for the bucket.Alternatively, assign the Dataplex Universal Catalog service account thefollowing permissions:storage.buckets.getstorage.objects.get
If you want to publish the data quality scan results asDataplex Universal Catalog metadata, you must be grantedthe BigQuery Data Editor (
roles/bigquery.dataEditor)IAM role for the table, and thedataplex.entryGroups.useDataQualityScorecardAspectpermission on the@bigqueryentry group in the same location as the table.Alternatively, you must be granted the Dataplex Catalog Editor(roles/dataplex.catalogEditor) role for the@bigqueryentry group in thesame location as the table.Alternatively, you need all of the following permissions:
bigquery.tables.update- on the tabledataplex.entryGroups.useDataQualityScorecardAspect- on the@bigqueryentry group
Or, you need all of the following permissions:
dataplex.entries.update- on the@bigqueryentry groupdataplex.entryGroups.useDataQualityScorecardAspect- on the@bigqueryentry group
If you need to access columns protected by BigQuery column-levelaccess policies, then assign the Dataplex Universal Catalog service accountpermissions for those columns. The user creating or updating a data scan alsoneeds permissions for the columns.
If a table has BigQuery row-level access policies enabled, then youcan only scan rows visible to the Dataplex Universal Catalog service account. Notethat the individual user's access privileges are not evaluated for row-levelpolicies.
Required data scan roles
To use auto data quality, ask your administrator to grant you one of the followingIAM roles:
- Full access to
DataScanresources: Dataplex DataScan Administrator (roles/dataplex.dataScanAdmin) - To create
DataScanresources: Dataplex DataScan Creator (roles/dataplex.dataScanCreator) on the project - Write access to
DataScanresources: Dataplex DataScan Editor (roles/dataplex.dataScanEditor) - Read access to
DataScanresources excluding rules and results:Dataplex DataScan Viewer (roles/dataplex.dataScanViewer) - Read access to
DataScanresources, including rules and results:Dataplex DataScan DataViewer (roles/dataplex.dataScanDataViewer)
The following table lists theDataScan permissions:
| Permission name | Grants permission to do the following: |
|---|---|
dataplex.datascans.create | Create aDataScan |
dataplex.datascans.delete | Delete aDataScan |
dataplex.datascans.get | View operational metadata such as ID or schedule, but not results and rules |
dataplex.datascans.getData | ViewDataScan details including rules and results |
dataplex.datascans.list | ListDataScans |
dataplex.datascans.run | Run aDataScan |
dataplex.datascans.update | Update the description of aDataScan |
dataplex.datascans.getIamPolicy | View the current IAM permissions on the scan |
dataplex.datascans.setIamPolicy | Set IAM permissions on the scan |
Define data quality rules
You can define data quality rules by usingbuilt-in rules orcustom SQL checks.If you're using the Google Cloud CLI, you can definethese rules in aJSON or YAML file.
The examples in the following sections show how to define a variety of data qualityrules. The rules validate a sample table that contains data about customer transactions.Assume the table has the following schema:
| Column name | Column type | Column description |
|---|---|---|
| transaction_timestamp | Timestamp | Timestamp of the transaction. The table is partitioned on this field. |
| customer_id | String | A customer ID in the format of 8 letters followed by 16 digits. |
| transaction_id | String | The transaction ID needs to be unique across the table. |
| currency_id | String | One of the supported currencies.The currency type must match one of the available currencies in the dimension tabledim_currency. |
| amount | float | Transaction amount. |
| discount_pct | float | Discount percentage. This value must be between 0 and 100. |
Define data quality rules using built-in rule types
The following example rules are based on built-in rule types. You can createrules based on built-in rule types using the Google Cloud console or the API.Dataplex Universal Catalog might recommend some of these rules.
| Column name | Rule Type | Suggested dimension | Rule parameters |
|---|---|---|---|
transaction_id | Uniqueness check | Uniqueness | Threshold:Not Applicable |
amount | Null check | Completeness | Threshold:100% |
customer_id | Regex (regular expression) check | Validity | Regular expression:^[0-9]{8}[a-zA-Z]{16}$Threshold: 100% |
currency_id | Value set check | Validity | Set of:USD,JPY,INR,GBP,CANThreshold: 100% |
Define data quality rules using custom SQL rules
To build custom SQL rules, use the following framework:
When you create a rule that evaluates one row at a time, create an expressionthat generates the number of successful rows when Dataplex Universal Catalogevaluates the query
SELECT COUNTIF(CUSTOM_SQL_EXPRESSION) FROM TABLE.Dataplex Universal Catalog checks the number of successful rows against thethreshold.When you create a rule that evaluates across the rows or uses a tablecondition, create an expression that returns success or failure whenDataplex Universal Catalog evaluates the query
SELECT IF(CUSTOM_SQL_EXPRESSION) FROM TABLE.When you create a rule that evaluates the invalid state of a dataset, providea statement that returns invalid rows. If any rows are returned, the rulefails. Omit the trailing semicolon from the SQL statement.
You can refer to a data source table and all of its precondition filters byusing the data reference parameter
${data()}in a rule, instead ofexplicitly mentioning the source table and its filters. Examples ofprecondition filters include row filters, sampling percents, and incrementalfilters. The${data()}parameter is case-sensitive.
The following example rules are based on custom SQL rules.
| Rule type | Rule description | SQL expression |
|---|---|---|
| Row condition | Checks if the value of thediscount_pct is between 0 and 100. | 0 <discount_pct ANDdiscount_pct <100 |
| Row condition | Reference check to validate thatcurrency_id is one of the supported currencies. | currency_id in (select id from my_project_id.dim_dataset.dim_currency) |
| Table condition | Aggregate SQL expression that checks if the averagediscount_pct is between 30% and 50%. | 30<avg(discount) AND avg(discount) <50 |
| Row condition | Checks if a date is not in the future. | TIMESTAMP(transaction_timestamp)< CURRENT_TIMESTAMP() |
| Table condition | A BigQuery user-defined function (UDF) to check that the average transaction amount is less than a predefined value per country. Create the (Javascript) UDF by running the following command: CREATE OR REPLACE FUNCTION myProject.myDataset.average_by_country ( country STRING, average FLOAT64) RETURNS BOOL LANGUAGE js AS R""" if (country = "CAN" && average< 5000){ return 1 } else if (country = "IND" && average< 1000){ return 1 } else { return 0 } """; | Example rule to check the average transaction amount forcountry=CAN.myProject.myDataset.average_by_country( "CAN", (SELECT avg(amount) FROM myProject.myDataset.transactions_table WHERE currency_id = 'CAN' )) |
| Table condition | ABigQuery ML predict clause to identify anomalies indiscount_pct. It checks if a discount should be applied based oncustomer,currency, andtransaction. The rule checks if the prediction matches the actual value, at least 99% of times. Assumption: The ML model is created before using the rule. Create the ML model using the following command:CREATE MODEL model-project-id.dataset-id.model-name OPTIONS(model_type='logistic_reg') AS SELECT IF(discount_pct IS NULL, 0, 1) AS label, IFNULL(customer_id, "") AS customer, IFNULL(currency_id, "") AS currency, IFNULL(amount, 0.0) AS amount FROM `data-project-id.dataset-id.table-names` WHERE transaction_timestamp< '2022-01-01'; | The following rule checks if prediction accuracy is greater than 99%.SELECT accuracy > 0.99 FROM ML.EVALUATE (MODEL model-project-id.dataset-id.model-name, ( SELECT customer_id, currency_id, amount, discount_pct FROM data-project-id.dataset-id.table-names WHERE transaction_timestamp > '2022-01-01'; ) ) |
| Row condition | ABigQuery ML predict function to identify anomalies indiscount_pct. The function checks if a discount should be applied based oncustomer,currency andtransaction. The rule identifies all the occurrences where the prediction didn't match. Assumption: The ML model is created before using the rule. Create the ML model using the following command:CREATE MODEL model-project-id.dataset-id.model-name OPTIONS(model_type='logistic_reg') AS SELECT IF(discount_pct IS NULL, 0, 1) AS label, IFNULL(customer_id, "") AS customer, IFNULL(currency_id, "") AS currency, IFNULL(amount, 0.0) AS amount FROM `data-project-id.dataset-id.table-names` WHERE transaction_timestamp< '2022-01-01'; | The following rule checks if the discount prediction matches with the actual for every row.IF(discount_pct > 0, 1, 0) =(SELECT predicted_label FROM ML.PREDICT( MODEL model-project-id.dataset-id.model-name, ( SELECT customer_id, currency_id, amount, discount_pct FROM data-project-id.dataset-id.table-names AS t WHERE t.transaction_timestamp = transaction_timestamp LIMIT 1 ) ) ) |
| SQL assertion | Validates if thediscount_pct is greater than 30% for today by checking whether any rows exist with a discount percent less than or equal to 30. | SELECT * FROM my_project_id.dim_dataset.dim_currency WHERE discount_pct<= 30 AND transaction_timestamp >= current_date() |
| SQL assertion (withdata reference parameter) | Checks if the The date filter The data reference parameter | SELECT * FROM ${data()} WHERE discount_pct > 30 |
Define data quality rules using the gcloud CLI
The following example YAML file uses some of the same rules as thesample rules using built-in types and thesample custom SQL rules. This YAML file also containsother specifications for the data quality scan, such as filters and samplingpercent. When you use the gcloud CLI to create or update a dataquality scan, you can use a YAML file like this as input to the--data-quality-spec-file argument.
rules:-uniquenessExpectation:{}column:transaction_iddimension:UNIQUENESS-nonNullExpectation:{}column:amountdimension:COMPLETENESSthreshold:1-regexExpectation:regex:'^[0-9]{8}[a-zA-Z]{16}$'column:customer_idignoreNull:truedimension:VALIDITYthreshold:1-setExpectation:values:-'USD'-'JPY'-'INR'-'GBP'-'CAN'column:currency_idignoreNull:truedimension:VALIDITYthreshold:1-rangeExpectation:minValue:'0'maxValue:'100'column:discount_pctignoreNull:truedimension:VALIDITYthreshold:1-rowConditionExpectation:sqlExpression:0 < `discount_pct` AND `discount_pct` < 100column:discount_pctdimension:VALIDITYthreshold:1-rowConditionExpectation:sqlExpression:currency_id in (select id from `my_project_id.dim_dataset.dim_currency`)column:currency_iddimension:VALIDITYthreshold:1-tableConditionExpectation:sqlExpression:30 < avg(discount_pct) AND avg(discount_pct) < 50dimension:VALIDITY-rowConditionExpectation:sqlExpression:TIMESTAMP(transaction_timestamp) < CURRENT_TIMESTAMP()column:transaction_timestampdimension:VALIDITYthreshold:1-sqlAssertion:sqlStatement:SELECT * FROM `my_project_id.dim_dataset.dim_currency` WHERE discount_pct > 100dimension:VALIDITYsamplingPercent:50rowFilter:discount_pct > 100postScanActions:bigqueryExport:resultsTable:projects/my_project_id/datasets/dim_dataset/tables/dim_currencynotificationReport:recipients:emails:-'222larabrown@gmail.com'-'cloudysanfrancisco@gmail.com'scoreThresholdTrigger:scoreThreshold:50jobFailureTrigger:{}jobEndTrigger:{}catalogPublishingEnabled:trueCreate a data quality scan
Console
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
ClickCreate data quality scan.
In theDefine scan window, fill in the following fields:
Optional: Enter aDisplay name.
Enter anID. See theresource naming conventions.
Optional: Enter aDescription.
In theTable field, clickBrowse. Choose the table to scan, andthen clickSelect.Only standard BigQuery tables aresupported.
For tables in multi-region datasets, choose a region where to createthe data scan.
To browse the tables organized within Dataplex Universal Catalog lakes,clickBrowse within Dataplex Lakes.
In theScope field, chooseIncremental orEntire data.
- If you chooseIncremental: In theTimestamp column field,select a column of type
DATEorTIMESTAMPfrom yourBigQuery table that increases as new records are added,and that can be used to identify new records. It can be a column thatpartitions the table.
- If you chooseIncremental: In theTimestamp column field,select a column of type
To filter your data, select theFilter rows checkbox. Provide arow filter consisting of a valid SQL expression that can be used as a part of a
WHEREclause in GoogleSQL syntax.For example,col1 >= 0.The filter can be a combination of multiple column conditions. Forexample,col1 >= 0 AND col2 < 10.To sample your data, in theSampling size list, select asampling percentage. Choose a percentage value that ranges between0.0% and 100.0% with up to 3 decimal digits. For largerdatasets, choose a lower sampling percentage. For example, for a1 PB table, if you enter a value between 0.1% and 1.0%,the data quality scan samples between 1-10 TB of data. Forincremental data scans, the data quality scan applies sampling to thelatest increment.
To publish the data quality scan results as Dataplex Universal Catalogmetadata, select thePublish results to BigQuery and Dataplex Catalog checkbox.
You can view the latest scan results on theData quality tab in theBigQuery and Dataplex Universal Catalog pages for the sourcetable. To enable users to access the published scan results, see theGrant access to data profile scan results sectionof this document.
In theSchedule section, choose one of the following options:
Repeat: Run the data quality scan on a schedule: hourly, daily,weekly, monthly, or custom. Specify how often the scan runs andat what time. If you choose custom, usecronformat to specify the schedule.
On-demand: Run the data quality scan on demand.
ClickContinue.
In theData quality rules window, define the rules toconfigure for this data quality scan.
ClickAdd rules, and then choose from the following options.
Profile based recommendations: Build rules from therecommendations based on an existing data profiling scan.
Choose columns: Select the columns to get recommended rules for.
Choose scan project: If the data profiling scan is in adifferent project than the project where you are creatingthe data quality scan, then select the project to pull profilescans from.
Choose profile results: Select one or more profile results andthen clickOK. This populates a list of suggested rules thatyou can use as a starting point.
Select the checkbox for the rules that you want to add, and thenclickSelect. Once selected, the rules are added to yourcurrent rule list. Then, you can edit the rules.
Built-in rule types: Build rules from predefined rules.See the list ofpredefined rules.
Choose columns: Select the columns to select rules for.
Choose rule types: Select the rule types that you want tochoose from, and then clickOK. The rule types that appeardepend on the columns that you selected.
Select the checkbox for the rules that you want to add, and thenclickSelect. Once selected, the rules are added to yourcurrent rules list. Then, you can edit the rules.
SQL row check rule: Create a custom SQL rule to apply to each row.
InDimension, choose one dimension.
InPassing threshold, choose a percentage of records that mustpass the check.
InColumn name, choose a column.
In theProvide a SQL expression field, enter a SQL expressionthat evaluates to a boolean
true(pass) orfalse(fail). Formore information, seeSupported custom SQL rule typesand the examples inDefine data quality rules.ClickAdd.
SQL aggregate check rule: Create a custom SQLtable condition rule.
InDimension, choose one dimension.
InColumn name, choose a column.
In theProvide a SQL expression field, enter a SQL expressionthat evaluates to a boolean
true(pass) orfalse(fail). Formore information, seeSupported custom SQL rule typesand the examples inDefine data quality rules.ClickAdd.
SQL assertion rule: Create a custom SQL assertion rule to checkfor an invalid state of the data.
InDimension, choose one dimension.
Optional: InColumn name, choose a column.
In theProvide a SQL statement field, enter a SQL statementthat returns rows that match the invalid state. If any rows arereturned, this rule fails. Omit the trailing semicolon from the SQLstatement. For more information, seeSupported custom SQL rule typesand the examples inDefine data quality rules.
ClickAdd.
Optional: For any data quality rule, you can assign a custom rule nameto use for monitoring and alerting, and a description. To do this,edit a rule and specify the following details:
- Rule name: Enter a custom rule name with up to 63 characters.The rule name can include letters (a-z, A-Z), digits (0-9), andhyphens (-) and must start with a letter and end with a numberor a letter.
- Description: Enter a rule description with a maximumlength of 1,024 characters.
Repeat the previous steps to add additional rules to the data qualityscan. When finished, clickContinue.
Optional: Export the scan results to a BigQuery standardtable. In theExport scan results to BigQuery table section, do thefollowing:
In theSelect BigQuery dataset field, clickBrowse. Select aBigQuery dataset to store the data quality scan results.
In theBigQuery table field, specify the table to store the dataquality scan results. If you're using an existing table, make surethat it is compatible with theexport table schema.If the specified table doesn't exist, Dataplex Universal Catalog createsit for you.
Note: You can use the same results table for multiple data qualityscans.
Optional: Add labels. Labels are key-value pairs that let you grouprelated objects together or with other Google Cloud resources.
Optional: Set up email notification reports to alert people about thestatus and results of a data quality scan job. In theNotification reportsection, clickAdd email ID andenter up to five email addresses. Then, select the scenarios that you wantto send reports for:
- Quality score (<=): sends a report when a job succeeds with a dataquality score that is lower than the specified target score. Enter atarget quality score between 0 and 100.
- Job failures: sends a report when the job itself fails, regardlessof the data quality results.
- Job completion (success or failure): sends a report when the jobends, regardless of the data quality results.
ClickCreate.
After the scan is created, you can run it at any time by clickingRun now.
gcloud
To create a data quality scan, use thegcloud dataplex datascans create data-quality command.
If the source data is organized in a Dataplex Universal Catalog lake, include the--data-source-entity flag:
gclouddataplexdatascanscreatedata-qualityDATASCAN\--location=LOCATION\--data-quality-spec-file=DATA_QUALITY_SPEC_FILE\--data-source-entity=DATA_SOURCE_ENTITYIf the source data isn't organized in a Dataplex Universal Catalog lake, includethe--data-source-resource flag:
gclouddataplexdatascanscreatedata-qualityDATASCAN\--location=LOCATION\--data-quality-spec-file=DATA_QUALITY_SPEC_FILE\--data-source-resource=DATA_SOURCE_RESOURCEReplace the following variables:
DATASCAN: The name of the data quality scan.LOCATION: The Google Cloud region in which tocreate the data quality scan.DATA_QUALITY_SPEC_FILE: The path to the JSON orYAML file containing the specifications for the data quality scan. The filecan be a local file or a Cloud Storage path with the prefixgs://.Use this file to specify the data quality rules for the scan. You can alsospecify additional details in this file, such as filters, sampling percent,and post-scan actions like exporting to BigQuery or sendingemail notification reports. See thedocumentation for JSON representationand theexample YAML representation.DATA_SOURCE_ENTITY: The Dataplex Universal Catalogentity that contains the data for the data quality scan. For example,projects/test-project/locations/test-location/lakes/test-lake/zones/test-zone/entities/test-entity.DATA_SOURCE_RESOURCE: The name of the resourcethat contains the data for the data quality scan. For example,//bigquery.googleapis.com/projects/test-project/datasets/test-dataset/tables/test-table.
REST
To create a data quality scan, use thedataScans.create method.
If you want to build rules for the data quality scan by using rulerecommendations that are based on the results of a data profiling scan, getthe recommendations by calling thedataScans.jobs.generateDataQualityRules methodon the data profiling scan.
Export table schema
To export the data quality scan results to an existing BigQuerytable, make sure that it is compatible with the following table schema:
| Column name | Column data type | Sub field name (if applicable) | Sub field data type | Mode | Example |
|---|---|---|---|---|---|
| data_quality_scan | struct/record | resource_name | string | nullable | //dataplex.googleapis.com/projects/test-project/locations/europe-west2/datascans/test-datascan |
project_id | string | nullable | dataplex-back-end-dev-project | ||
location | string | nullable | us-central1 | ||
data_scan_id | string | nullable | test-datascan | ||
| data_source | struct/record | resource_name | string | nullable | Entity case://dataplex.googleapis.com/projects/dataplex-back-end-dev-project/locations/europe-west2/lakes/a0-datascan-test-lake/zones/a0-datascan-test-zone/entities/table1Table case: //bigquery.googleapis.com/projects/test-project/datasets/test-dataset/tables/test-table |
dataplex_entity_project_id | string | nullable | dataplex-back-end-dev-project | ||
dataplex_entity_project_number | integer | nullable | 123456789 | ||
dataplex_lake_id | string | nullable | (Valid only if source is entity)test-lake | ||
dataplex_zone_id | string | nullable | (Valid only if source is entity)test-zone | ||
dataplex_entity_id | string | nullable | (Valid only if source is entity)test-entity | ||
table_project_id | string | nullable | test-project | ||
table_project_number | integer | nullable | 987654321 | ||
dataset_id | string | nullable | (Valid only if source is table)test-dataset | ||
table_id | string | nullable | (Valid only if source is table)test-table | ||
| data_quality_job_id | string | nullable | caeba234-cfde-4fca-9e5b-fe02a9812e38 | ||
| data_quality_job_configuration | json | trigger | string | nullable | ondemand/schedule |
incremental | boolean | nullable | true/false | ||
sampling_percent | float | nullable | (0-100)20.0 (indicates 20%) | ||
row_filter | string | nullable | col1 >= 0 AND col2< 10 | ||
| job_labels | json | nullable | {"key1":value1} | ||
| job_start_time | timestamp | nullable | 2023-01-01 00:00:00 UTC | ||
| job_end_time | timestamp | nullable | 2023-01-01 00:00:00 UTC | ||
| job_rows_scanned | integer | nullable | 7500 | ||
| rule_name | string | nullable | test-rule | ||
| rule_type | string | nullable | Range Check | ||
| rule_evaluation_type | string | nullable | Per row | ||
| rule_column | string | nullable | Rule only attached to a certain column | ||
| rule_dimension | string | nullable | UNIQUENESS | ||
| job_quality_result | struct/record | passed | boolean | nullable | true/false |
score | float | nullable | 90.8 | ||
| job_dimension_result | json | nullable | {"ACCURACY":{"passed":true,"score":100},"CONSISTENCY":{"passed":false,"score":60}} | ||
| rule_threshold_percent | float | nullable | (0.0-100.0)Rule-threshold-pct in API * 100 | ||
| rule_parameters | json | nullable | {min: 24, max:5345} | ||
| rule_pass | boolean | nullable | True | ||
| rule_rows_evaluated | integer | nullable | 7400 | ||
| rule_rows_passed | integer | nullable | 3 | ||
| rule_rows_null | integer | nullable | 4 | ||
| rule_failed_records_query | string | nullable | "SELECT * FROM `test-project.test-dataset.test-table` WHERE (NOT((`cTime` >= '15:31:38.776361' and `cTime`<= '19:23:53.754823') IS TRUE));" | ||
| rule_assertion_row_count | integer | nullable | 10 |
rule_assertion_row_count is only applicable forSQL Assertion rule.When you configureBigQueryExportfor a data quality scan job, follow these guidelines:
- For the field
resultsTable, use the format://bigquery.googleapis.com/projects/{project-id}/datasets/{dataset-id}/tables/{table-id}. - Use a BigQuery standard table.
- If the table doesn't exist when the scan is created or updated,Dataplex Universal Catalog creates the table for you.
- By default, the table is partitioned on the
job_start_timecolumn daily. - If you want the table to be partitioned in other configurations or ifyou don't want the partition, then recreate the table with the requiredschema and configurations and then provide the pre-created table as theresults table.
- Make sure the results table is in the same location as the source table.
- If VPC-SC is configured on the project, then the results table must be in thesame VPC-SC perimeter as the source table.
- If the table is modified during the scan execution stage, then the currentrunning job exports to the previous results table and the table changetakes effect from the next scan job.
- Don't modify the table schema. If you need customized columns, create a viewupon the table.
- To reduce costs, set an expiration on the partition based on your use case.For more information, see how toset the partition expiration.
Run a data quality scan
Console
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
Click the data quality scan to run.
ClickRun now.
gcloud
To run a data quality scan, use thegcloud dataplex datascans run command:
gcloud dataplex datascans runDATASCAN \--location=LOCATION \
Replace the following variables:
LOCATION: The Google Cloud region in which thedata quality scan was created.DATASCAN: The name of the data quality scan.
REST
To run a data quality scan, use thedataScans.run method.
View the data quality scan results
Console
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
Click the name of a data quality scan.
TheOverview section displays information about the most recentjobs, including when the scan was run, the number of recordsscanned in each job, whether all the data quality checks passed, andif there were failures, the number of data quality checks that failed.
TheData quality scan configuration section displays details about thescan.
To see detailed information about a job, such as data quality scores thatindicate the percentage of rules that passed, which rules failed, and thejob logs, click theJobs history tab. Then, click a job ID.
gcloud
To view the results of a data quality scan job, use thegcloud dataplex datascans jobs describe command:
gcloud dataplex datascans jobs describeJOB \--location=LOCATION \--datascan=DATASCAN \--view=FULL
Replace the following variables:
JOB: The job ID of the data quality scan job.LOCATION: The Google Cloud region in which the dataquality scan was created.DATASCAN: The name of the data quality scan the jobbelongs to.--view=FULL: To see the scan job result, specifyFULL.
REST
To view the results of a data quality scan, use thedataScans.get method.
View published results
If the data quality scan results are published as Dataplex Universal Catalogmetadata, then you can see the latest scan resultson the BigQuery and Dataplex Universal Catalog pages in theGoogle Cloud console, on the source table'sData quality tab.
In the Google Cloud console, go to the Dataplex Universal CatalogSearchpage.
Search for and then select the table.
Click theData quality tab.
The latest published results are displayed.
Note: Published results might not be available if a scan is running for the firsttime.
View historical scan results
Dataplex Universal Catalog saves the data quality scan history of the last 300jobs or for the past year, whichever occurs first.
Console
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
Click the name of a data quality scan.
Click theJobs history tab.
TheJobs history tab provides information about past jobs, such asthe number of records scanned in each job, the job status, the timethe job was run, and whether each rule passed or failed.
To view detailed information about a job, click any of the jobs in theJob ID column.
gcloud
To view historical data quality scan jobs, use thegcloud dataplex datascans jobs list command:
gcloud dataplex datascans jobs list \--location=LOCATION \--datascan=DATASCAN \
Replace the following variables:
LOCATION: The Google Cloud region in which the dataquality scan was created.DATASCAN: The name of the data quality scan to viewhistorical jobs for.
REST
To view historical data quality scan jobs, use thedataScans.jobs.list method.
Grant access to data quality scan results
To enable the users in your organization to view the scan results, do the following:
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
Click the data quality scan you want to share the results of.
Click thePermissions tab.
Do the following:
- To grant access to a principal, clickGrant access. Grant theDataplex DataScan DataViewer role to theassociated principal.
- To remove access from a principal, select the principal that youwant to remove theDataplex DataScan DataViewer role from. ClickRemove access, and then confirm when prompted.
Set alerts in Cloud Logging
To set alerts for data quality failures using the logs in Cloud Logging,follow these steps:
Console
In the Google Cloud console, go to the Cloud LoggingLogs Explorer.
In theQuery window, enter your query. Seesample queries.
ClickRun Query.
ClickCreate alert. This opens a side panel.
Enter your alert policy name and clickNext.
Review the query.
Click thePreview Logs button to test your query. This shows logswith matching conditions.
ClickNext.
Set the time between notifications and clickNext.
Define who should be notified for the alert and clickSave to createthe alert policy.
Alternatively, you can configure and edit your alerts by navigating in theGoogle Cloud console toMonitoring>Alerting.
gcloud
Not supported.
REST
For more information about how to set alerts in Cloud Logging, seeCreate a log-based alerting policy by using the Monitoring API.
Sample queries for setting job level or dimension level alerts
A sample query to set alerts on overall data quality failures for a data qualityscan:
resource.type="dataplex.googleapis.com/DataScan"AND labels."dataplex.googleapis.com/data_scan_state"="SUCCEEDED"AND resource.labels.resource_container="projects/112233445566"AND resource.labels.datascan_id="a0-test-dec6-dq-3"AND NOT jsonPayload.dataQuality.passed=trueA sample query to set alerts on data quality failures for a dimension(for example, uniqueness) of a given data quality scan:
resource.type="dataplex.googleapis.com/DataScan"AND labels."dataplex.googleapis.com/data_scan_state"="SUCCEEDED"AND resource.labels.resource_container="projects/112233445566"AND resource.labels.datascan_id="a0-test-dec6-dq-3"AND jsonPayload.dataQuality.dimensionPassed.UNIQUENESS=falseA sample query to set alerts on data quality failures for a table.
Set alerts on data quality failures for a BigQuery table thatisn't organized in a Dataplex Universal Catalog lake:
resource.type="dataplex.googleapis.com/DataScan"AND jsonPayload.dataSource="//bigquery.googleapis.com/projects/test-project/datasets/testdataset/table/chicago_taxi_trips"AND labels."dataplex.googleapis.com/data_scan_state"="SUCCEEDED"AND resource.labels.resource_container="projects/112233445566"AND NOT jsonPayload.dataQuality.passed=trueSet alerts on data quality failures for a BigQuery tablethat's organized in a Dataplex Universal Catalog lake:
resource.type="dataplex.googleapis.com/DataScan"AND jsonPayload.dataSource="projects/test-project/datasets/testdataset/table/chicago_taxi_trips"AND labels."dataplex.googleapis.com/data_scan_state"="SUCCEEDED"AND resource.labels.resource_container="projects/112233445566"AND NOT jsonPayload.dataQuality.passed=true
Sample queries to set per rule alerts
A sample query to set alerts on all failing data quality rules with thespecified custom rule name for a data quality scan:
resource.type="dataplex.googleapis.com/DataScan"AND jsonPayload.ruleName="custom-name"AND jsonPayload.result="FAILED"A sample query to set alerts on all failing data quality rules of a specificevaluation type for a data quality scan:
resource.type="dataplex.googleapis.com/DataScan"AND jsonPayload.evalutionType="PER_ROW"AND jsonPayload.result="FAILED"A sample query to set alerts on all failing data quality rules for a columnin the table used for a data quality scan:
resource.type="dataplex.googleapis.com/DataScan"AND jsonPayload.column="CInteger"AND jsonPayload.result="FAILED"
Troubleshoot a data quality failure
For each job with row-level rules that fail, Dataplex Universal Catalog providesa query to get the failed records. Run this query to see the records that didnot match your rule.
Note: The query returns all of the columns of the table, not just the failedcolumn.Console
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
Click the name of the data quality scan whose records you want to troubleshoot.
Click theJobs history tab.
Click the job ID of the job that identified data quality failures.
In the job results window that opens, in theRules section, find the columnQuery to get failed records. ClickCopy query to clipboard for thefailed rule.
Run the query in BigQueryto see the records that caused the job to fail.
gcloud
Not supported.
REST
To get the job that identified data quality failures, use the
dataScans.getmethod.In the response object, the
failingRowsQueryfield shows the query.Run the query in BigQueryto see the records that caused the job to fail.
Manage data quality scans for a specific table
The steps in this document show how to manage data profile scans across yourproject by using the Dataplex Universal CatalogData profiling & quality pagein the Google Cloud console.
You can also create and manage data profile scans when working with aspecific table. In the Google Cloud console, on the Dataplex Universal Catalogpage for the table, use theData quality tab. Do the following:
In the Google Cloud console, go to the Dataplex Universal CatalogSearch page.
Search for and then select the table.
Click theData quality tab.
Depending on whether the table has a data quality scan whose results arepublished as Dataplex Universal Catalog metadata, you can work with the table'sdata quality scans in the following ways:
Data quality scan results are published: the latest scan results aredisplayed on the page.
To manage the data quality scans for this table, clickData qualityscan, and then select from the following options:
Create new scan: create a new data quality scan. For moreinformation, see theCreate a data quality scan sectionof this document. When you create a scan from a table's details page, thetable is preselected.
Run now: run the scan.
Edit scan configuration: edit settings including the display name,filters, and schedule.
To edit the data quality rules, on theData quality tab, click theRules tab. ClickModify rules. Update the rules and then clickSave.
Manage scan permissions: control who can access the scan results.For more information, see theGrant access to data quality scan resultssection of this document.
View historical results: view detailed information about previousdata quality scan jobs. For more information, see theView data quality scan results andView historical scan results sections ofthis document.
View all scans: view a list of data quality scans that apply to thistable.
Data quality scan results aren't published: select from thefollowing options:
Create data quality scan: create a new data quality scan. For moreinformation, see theCreate a data quality scan sectionof this document. When you create a scan from a table's details page, thetable is preselected.
View existing scans: view a list of data quality scans that apply tothis table.
Update a data quality scan
You can edit various settings for an existing data quality scan, such as thedisplay name, filters, schedule, and data quality rules.
Note: If an existing data quality scan publishes the results to theBigQuery and Dataplex Universal Catalog pages in theGoogle Cloud console, and you instead want to publish future scan results asDataplex Universal Catalog metadata, you must edit the scan and reenable publishing.You might need additional permissions to enable catalog publishing.Console
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
Click the name of a data quality scan.
To edit settings including the display name, filters, and schedule, clickEdit. Edit the values and then clickSave.
To edit the data quality rules, on the scan details page, click theCurrent rules tab. ClickModify rules. Update the rules andthen clickSave.
gcloud
To update the description of a data quality scan, use thegcloud dataplex datascans update data-quality command:
gcloud dataplex datascans update data-qualityDATASCAN \--location=LOCATION \--description=DESCRIPTION
Replace the following:
DATASCAN: The name of the data quality scan toupdate.LOCATION: The Google Cloud region in which the dataquality scan was created.DESCRIPTION: The new description for the dataquality scan.
rules,rowFilter, orsamplingPercent, in the data quality specification file. Refer toJSON andYAML representations.REST
To edit a data quality scan, use thedataScans.patch method.
Delete a data quality scan
Console
In the Google Cloud console, go to the Dataplex Universal CatalogData profiling & quality page.
Click the scan you want to delete.
ClickDelete, and then confirm when prompted.
gcloud
To delete a data quality scan, use thegcloud dataplex datascans delete command:
gcloud dataplex datascans deleteDATASCAN \--location=LOCATION \--async
Replace the following variables:
DATASCAN: The name of the data quality scan todelete.LOCATION: The Google Cloud region in which the dataquality scan was created.
REST
To delete a data quality scan, use thedataScans.delete method.
What's next?
- Follow acodelab: use AI assistance to facilitate programmatic data quality.
- Learn aboutdata profiling.
- Learn how touse data profiling.
- Follow a tutorial tomanage data quality rules as code with Terraform.
Except as otherwise noted, the content of this page is licensed under theCreative Commons Attribution 4.0 License, and code samples are licensed under theApache 2.0 License. For details, see theGoogle Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.
Last updated 2025-10-24 UTC.