Add second index (Scala)

database/sql/src/main/scala/cromwell/database/slick/tables/MetadataEntryComponent.scala

@@ -56,24 +56,34 @@ trait MetadataEntryComponent {
     ) <> (MetadataEntry.tupled, MetadataEntry.unapply)
 
     // TODO: rename index via liquibase
+    // TODO: may be possible to drop once we fully deploy the below indexes with leading UUID
     def ixMetadataEntryWeu = index("METADATA_WORKFLOW_IDX", workflowExecutionUuid, unique = false)
 
     /**
-      * Index designed to accelerate common key-specific queries across an entire workflow, such as:
+      * Index designed to accelerate common key-specific queries across an entire workflow such as:
       * - Get me workflow-level `outputs%` (no tasks, requireEmptyJobKey = true)
       * - Get me all `vmStartTime%`, `vmEndTime%`, `vmCostPerHour%` in the workflow (include tasks, requireEmptyJobKey = false)
       *
-      * It is NOT good, as in may make actively slower, queries that reference a specific job. If we do more
-      * with getting metadata for individual jobs, recommend creating this index with all 5 columns:
-      * - WORKFLOW_EXECUTION_UUID, CALL_FQN, JOB_SCATTER_INDEX, JOB_RETRY_ATTEMPT, METADATA_KEY
-      *
-      * Do NOT recommend this alternate order, as wildcards in the middle are inefficient and this can be
-      * slower than no indexes. Tested with 20M row `69e8259c` workflow in October 2024.
-      * - WORKFLOW_EXECUTION_UUID, METADATA_KEY, CALL_FQN, JOB_SCATTER_INDEX, JOB_RETRY_ATTEMPT
+      * It is NOT good, as in may make actively slower, queries that reference a specific job.
       *
       * @return A reference to the index
       */
     def ixMetadataEntryWeuMk = index("IX_METADATA_ENTRY_WEU_MK", (workflowExecutionUuid, metadataKey), unique = false)
+
+    /**
+      * Index designed to accelerate task/attempt level queries such as:
+      * - Get some keys for a specific attempt
+      * - Get all rows for a specific attempt
+      * - Get all rows for a specific call/scatter, across all attempts
+      * - Get unique call names in a workflow
+      *
+      * @return A reference to the index
+      */
+    def ixMetadataEntryWeuCfJsiJraMk =
+      index("IX_METADATA_ENTRY_WEU_CF_JSI_JRA_MK",
+            (workflowExecutionUuid, callFullyQualifiedName, jobIndex, jobAttempt, metadataKey),
+            unique = false
+      )
   }
 
   val metadataEntries = TableQuery[MetadataEntries]