Version 1.2.0 or Newer

Alation Cloud Service Applies to Alation Cloud Service instances of Alation

Customer Managed Applies to customer-managed instances of Alation

Important

This section is applicable for Alation Version 2023.3.4 or higher and PostgreSQL OCF connector Version 1.2.0 or higher.

Query log ingestion (QLI) extracts and ingests the query history of a database and powers the lineage, popularity, top user, and join and filter information in the catalog. Explore examples of ingested queries on schema and table catalog pages.

Alation supports the following PostgreSQL deployment: Amazon EC2, Amazon RDS, and EDB Postgres Server.

Configure QLI for PostgreSQL on Amazon EC2 and Enterprise

The steps involved in configuring and running QLI for PostgreSQL on Amazon EC2, EDB Postgres Server (PostgreSQL Enterprise), or a generic on-premise are:

1. Configure View-Based QLI or Configure Custom Query-Based QLI

2. Test the Access and Find the Query History Size

3. Preview Results

4. Run QLI

You can configure query log ingestion on the Query Log Ingestion tab of the Settings page. You can choose to configure QLI in one of the following ways:

• View-Based

• Custom Query-Based

Configure View-Based QLI

Prerequisite

Before configuring view-based QLI in Alation, you must perform the QLI setup for PostgreSQL on EC2 or EDB Postgres Server (PostgreSQL Enterprise). For more information, see PostgreSQL On Amazon EC2 and Enterprise Query Log Ingestion.

Provide the QLI View Name

Important

The Alation user interface displays standard configuration settings for credentials and connection information stored in the Alation database. If your organization has configured Azure KeyVault or AWS Secrets Manager to hold such information, the user interface will change to include the following buttons adjacent to the respective fields:

By default, you see the user interface for Standard. In the case of Vault, instead of the actual credential information, you must select the source and provide the corresponding key. For details, see Configure Secrets for OCF Connector Settings.

1. On the PostgreSQL connector page, go to the Query Log Ingestion tab of the Settings page.

2. Under the Provide the QLI view name section, enter the QLI view name in the View name field. For example: public.alation_postgres_logv (see PostgreSQL On Amazon EC2 and Enterprise Query Log Ingestion).

   Important

   Use the format schema_name.view_name.

3. Click Save.

Configure Custom Query-Based QLI

To configure custom query-based QLI, you must:

• Use the QLI query template to create a query structure

• Provide the custom query in Alation

Use the QLI Query Template

The template for the QLI query is given below. You can customize it by adding, removing, or changing the filter, but the columns and their aliases must remain as is since Alation expects this query structure.

No pgAudit ExtensionpgAudit Extension

SELECT
    userName,
    startTime,
    queryString,
    sessionId,
    sessionStarttime,
    transactionid,
    'N' AS cancelled,
    defaultDatabases
FROM <VIEW_NAME>
WHERE sessionStarttime >= TO_DATE(STARTTIME, 'YYYY-MM-DD HH24:MI:SS')
    AND sessionStarttime < TO_DATE(ENDTIME, 'YYYY-MM-DD HH24:MI:SS')
ORDER BY transactionid

The query should have <userName, startTime, queryString, defaultDatabases, sessionID, sessionStartTime, cancelled, transactionid> columns in the SELECT statement.

Note

• When using the QLI query example, do not substitute the STARTTIME and ENDTIME parameters in the WHERE filter. These parameters are not actual column names and should stay as is. They are expected by the connector and will be substituted with the start and end date of the QLI range selected in the user interface when QLI is run manually or on schedule.

• Ensure that you include the transactionid column in the query to record correct duration for ingested queries.

• The result set must be sorted based on the transactionid column to accurately calculate the correct duration for ingested queries.

Provide the Custom Query

1. On the PostgreSQL data source, go to the Query Log Ingestion tab of the Settings page.

2. Under the Provide the QLI view name section, go to Alternatively, use a custom SQL query.

3. In the Custom QLI Query field, provide a custom query to retrieve the query history.

4. Click Save.

Test the Access and Find the Query History Size

Before you perform the QLI, you must validate that the service account has access to the QLI view and gauge the approximate size of the query history metadata. The size is estimated based on the average query volume of the last 7 days.

To test the access and find out the approximate size of the query history metadata, perform these steps:

1. On the Settings page of your PostgreSQL data source, go to the Query Log Ingestion tab.

2. Under the Test access and query history size section, click Test.

   A dialog box appears displaying the access validation result and upon successful validation, the size of the query history is displayed. The size is estimated based on the query volume of the last 7 days.

   Note

   If the average query size for the last seven days exceeds 500k, a warning message indicates the same.

Preview Results

Before performing QLI, you can preview the queries that are ingested.

1. On the Settings page of your PostgreSQL data source, click go to the Query Log Ingestion tab.

2. Under the Preview Results section, enter the date range for which you want to generate the preview of the query history.

3. Click Preview.

4. Click View Results to view the generated preview. The Preview dialog appears displaying the total number of query statements per user under the User Queries tab and a detailed query statement under the Statements tab.

5. Click Download to download the detailed query statement as a JSON file.

   Note

   You can use this option to run default QLI using just the date range.

Run QLI

You can either run QLI manually on demand or configure it to run automatically on a schedule.

Run QLI Manually

To perform QLI manually on demand:

1. On the Settings page of your PostgreSQL data source, go to the Query Log Ingestion tab.

2. Under the Run QLI section, disable the Enable QLI Schedule toggle.

3. Specify the desired date range using the Date Range calendar widgets. You will need to specify the start date and the end date separately.

4. Click Import.

   A query log ingestion job is initiated.

Schedule QLI

1. On the Settings page of your PostgreSQL data source, go to the Query Log Ingestion tab.

2. Under the Run QLI section, enable the Enable QLI Schedule toggle.

3. Specify values for the job recurrence and time. The values are set in your local time.

   

Note

Here are some of the recommended schedules for better performance:

• Schedule QLI to run for every 12 hours at the 30th minute of the hour

• Schedule QLI to run for every 2 days at 11:30 PM

• Schedule QLI to run every week on the Sunday and Wednesday of the week

• Schedule QLI to run for every 3 months on the 15th day of the month

4. Click Import.

The next QLI runs on the set schedule.

View the Job Status

To view the QLI job status after you run the QLI manually or after Alation triggers the QLI as per the schedule, go to Query Log Ingestion > QLI Job Status.

The Query log ingestion job status table logs the following status:

• Succeeded - Indicates that the query ingestion was successful.

• Partial Success - Indicates that the query ingestion was successful with warnings. If Alation fails to ingest some of the objects during the QLI, it skips them and proceeds with the query ingestion, resulting in partial success.

• Failed - Indicates that the query ingestion failed with errors.

Click the View Details link to view a detailed report of query ingestion. Click the View Details link to view a detailed report of metadata extraction. If there are errors, the Job errors table displays the error category, error message, and a hint (ways to resolve the issue). Follow the instructions under the Hints column to resolve the error.

Configure QLI for PostgreSQL on Amazon RDS

To configure QLI for PostgreSQL on Amazon RDS, PostgreSQL Connector RDS: Query Log Ingestion.