WX-1676 Drop workflow store status index IX_WORKFLOW_STORE_ENTRY_WS (#7452)

Author: aednichols

CHANGELOG.md

@@ -21,6 +21,11 @@ such as "PAPI error code 9", "no available zones", and/or "quota too low".
 
 Resolved a hotspot in Cromwell to make the `size()` engine function perform much faster on file arrays. Common examples of file arrays could include globs or scatter-gather results. This enhancement applies only to WDL 1.0 and later, because that's when `size()` added [support for arrays](https://github.com/openwdl/wdl/blob/main/versions/1.0/SPEC.md#acceptable-compound-input-types).
 
+### Database migration
+
+The `IX_WORKFLOW_STORE_ENTRY_WS` index is removed from `WORKFLOW_STORE_ENTRY`.
+
+The index had low cardinality and workflow pickup is faster without it. Migration time depends on workflow store size, but should be very fast for most installations. Terminal workflows are removed from the workflow store, so only running workflows contribute to the cost.
 
 ## 87 Release Notes
 

database/migration/src/main/resources/changelog.xml

@@ -90,6 +90,7 @@
     <include file="changesets/enlarge_docker_hash_store_entry_id.xml" relativeToChangelogFile="true" />
     <include file="changesets/enlarge_workflow_store_entry_id.xml" relativeToChangelogFile="true" />
     <include file="changesets/enlarge_sub_workflow_store_entry_id.xml" relativeToChangelogFile="true" />
+    <include file="changesets/workflow_store_drop_state_index.xml" relativeToChangelogFile="true" />
     <!-- WARNING!
       This changeset should always be last.
       It is always run (and should always run last) to set table ownership correctly.

database/migration/src/main/resources/changesets/workflow_store_drop_state_index.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<databaseChangeLog objectQuotingStrategy="QUOTE_ALL_OBJECTS"
+                   xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
+                   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+                   xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.3.xsd">
+
+    <!-- This index had low cardinality, we found that ignoring it yielded empirically better performance -->
+    <changeSet author="anichols" id="workflow_store_drop_state_index" dbms="mysql,hsqldb,postgresql,mariadb">
+        <dropIndex tableName="WORKFLOW_STORE_ENTRY" indexName="IX_WORKFLOW_STORE_ENTRY_WS"/>
+    </changeSet>
+
+</databaseChangeLog>

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

@@ -62,8 +62,6 @@ trait WorkflowStoreEntryComponent {
     ) <> ((WorkflowStoreEntry.apply _).tupled, WorkflowStoreEntry.unapply)
 
     def ucWorkflowStoreEntryWeu = index("UC_WORKFLOW_STORE_ENTRY_WEU", workflowExecutionUuid, unique = true)
-
-    def ixWorkflowStoreEntryWs = index("IX_WORKFLOW_STORE_ENTRY_WS", workflowState, unique = false)
   }
 
   protected val workflowStoreEntries = TableQuery[WorkflowStoreEntries]