The correct answer is Kusto Query Language (KQL).

The telemetry from Azure SQL Database Intelligent Insights and from Application Insights is collected into Azure Monitor Logs and Log Analytics where the native query language is Kusto Query Language (KQL). Kusto Query Language (KQL) is designed for interactive ad hoc queries over telemetry and log data and it provides rich operators for filtering, summarizing, joining, and time series analysis which make exploratory queries fast and expressive.

Transact-SQL is the SQL dialect used to query relational data in SQL Server and Azure SQL Database. It is not the native language for querying Azure Monitor or Application Insights logs so it is not appropriate for ad hoc telemetry queries in this scenario.

PL/pgSQL is a procedural extension for PostgreSQL and it applies to PostgreSQL databases. It is unrelated to Azure Monitor Logs and cannot be used to query Application Insights telemetry.

BigQuery SQL is the SQL dialect used by Google BigQuery. It is a Google Cloud product and is not used to query Azure Monitor or Application Insights data.

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