From a66528d14f69cd8ae37f31cd3dc91a12db0c56ea Mon Sep 17 00:00:00 2001
From: Pierre GIRAUD <pierre.giraud@dalibo.com>
Date: Thu, 10 Oct 2024 11:58:17 +0200
Subject: [PATCH] Estimate number of launched workers from gather node

If the count is not available in the node itself.

Fixes #578
---
 src/enums.ts                 | 1 +
 src/node.ts                  | 3 +++
 src/services/plan-service.ts | 3 +++
 3 files changed, 7 insertions(+)

diff --git a/src/enums.ts b/src/enums.ts
index 3168a382..b4816f73 100644
--- a/src/enums.ts
+++ b/src/enums.ts
@@ -127,6 +127,7 @@ export enum NodeProp {
   AVERAGE_IO_WRITE_TIME = "*I/O Write Speed (exclusive)",
 
   WORKERS_PLANNED_BY_GATHER = "*Workers Planned By Gather",
+  WORKERS_LAUNCHED_BY_GATHER = "*Workers Launched By Gather",
 
   CTE_SCAN = "CTE Scan",
   CTE_NAME = "CTE Name",
diff --git a/src/node.ts b/src/node.ts
index 5c648019..1badb8c0 100644
--- a/src/node.ts
+++ b/src/node.ts
@@ -245,6 +245,9 @@ export default function useNode(
     if (node[NodeProp.WORKERS_LAUNCHED]) {
       return node[NodeProp.WORKERS_LAUNCHED] as number
     }
+    if (node[NodeProp.WORKERS_LAUNCHED_BY_GATHER]) {
+      return node[NodeProp.WORKERS_LAUNCHED_BY_GATHER] as number
+    }
     const workers = node[NodeProp.WORKERS] as Worker[]
     return workers ? workers.length : NaN
   })
diff --git a/src/services/plan-service.ts b/src/services/plan-service.ts
index 12e3937f..3fcd4db1 100644
--- a/src/services/plan-service.ts
+++ b/src/services/plan-service.ts
@@ -89,6 +89,9 @@ export class PlanService {
         child[NodeProp.WORKERS_PLANNED_BY_GATHER] =
           node[NodeProp.WORKERS_PLANNED] ||
           node[NodeProp.WORKERS_PLANNED_BY_GATHER]
+        child[NodeProp.WORKERS_LAUNCHED_BY_GATHER] =
+          node[NodeProp.WORKERS_LAUNCHED] ||
+          node[NodeProp.WORKERS_LAUNCHED_BY_GATHER]
       }
       if (this.isCTE(child)) {
         plan.ctes.push(child)