From 413ea727054d5ce39880ef6478df3031523bc0dd Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Fri, 10 Nov 2023 09:59:28 +0100
Subject: [PATCH] perf: optimize session variables in HANA

---
 hana/lib/HANAService.js         | 7 +------
 hana/lib/drivers/base.js        | 5 +++++
 hana/lib/drivers/hana-client.js | 4 ++++
 hana/lib/drivers/hdb.js         | 5 +++++
 4 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/hana/lib/HANAService.js b/hana/lib/HANAService.js
index 0309b5d9e..0212a9b42 100644
--- a/hana/lib/HANAService.js
+++ b/hana/lib/HANAService.js
@@ -64,12 +64,7 @@ class HANAService extends SQLService {
   }
 
   async set(variables) {
-    const columns = Object.keys(variables).map(
-      k => `SET '${k.replace(/'/g, "''")}'='${(variables[k] + '').replace(/'/g, "''")}';`,
-    )
-    const sql = `DO BEGIN ${columns.join('')} END;`
-
-    await this.dbc.exec(sql)
+    this.dbc.set(variables)
   }
 
   async onSELECT({ query, data }) {
diff --git a/hana/lib/drivers/base.js b/hana/lib/drivers/base.js
index a9a265287..b2dd83d06 100644
--- a/hana/lib/drivers/base.js
+++ b/hana/lib/drivers/base.js
@@ -90,6 +90,11 @@ class HANADriver {
     return prom(this._native, 'exec')(sql)
   }
 
+  set(variables) {
+    variables
+    throw new Error('Implementation missing')
+  }
+
   /**
    * Commits the current transaction
    */
diff --git a/hana/lib/drivers/hana-client.js b/hana/lib/drivers/hana-client.js
index e11a29b2d..ff324c1b7 100644
--- a/hana/lib/drivers/hana-client.js
+++ b/hana/lib/drivers/hana-client.js
@@ -19,6 +19,10 @@ class HANAClientDriver extends driver {
     this._native.setAutoCommit(false)
   }
 
+  set(variables) {
+    Object.keys(variables).forEach(k => this._native.setClientInfo(k, variables[k]))
+  }
+
   async prepare(sql) {
     const ret = await super.prepare(sql)
     ret.stream = async (values, one) => {
diff --git a/hana/lib/drivers/hdb.js b/hana/lib/drivers/hdb.js
index 6a6d43355..9ee4a1650 100644
--- a/hana/lib/drivers/hdb.js
+++ b/hana/lib/drivers/hdb.js
@@ -26,6 +26,11 @@ class HDBDriver extends driver {
     this.connected = false
   }
 
+  set(variables) {
+    const clientInfo = this._native._connection.getClientInfo()
+    Object.keys(variables).forEach(k => clientInfo.setProperty(k, variables[k]))
+  }
+
   async prepare(sql) {
     const ret = await super.prepare(sql)
     ret.stream = async (values, one) => {