From 25590a0372f7bca3f966502015648f3a1a9a6a0b Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Wed, 15 Nov 2023 11:42:24 +0100
Subject: [PATCH 01/10] Initial implementation for stream entries

---
 db-service/lib/cqn2sql.js          | 51 +++++++++++++++++++++++++++---
 sqlite/test/general/stream.test.js | 14 ++++----
 2 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/db-service/lib/cqn2sql.js b/db-service/lib/cqn2sql.js
index c74703bd5..0b6ee9f1d 100644
--- a/db-service/lib/cqn2sql.js
+++ b/db-service/lib/cqn2sql.js
@@ -423,12 +423,55 @@ class CQN2SQLRenderer {
       .filter(a => a)
       .map(c => c.sql)
 
+    // REVISIT: yield less often
+    const stringify = async function* (entries) {
+      yield '['
+
+      let sep = ''
+      for (const row of entries) {
+        if (!sep) sep = ','
+        else yield sep
+
+        let sepsub = ''
+        yield '{'
+        for (const key in row) {
+
+          if (!sepsub) sepsub = ','
+          else yield sepsub
+
+          yield JSON.stringify(key)
+          yield ':'
+
+          const val = row[key]
+          if (val instanceof Readable) {
+            yield '"'
+
+            // TODO: double check that it works
+            val.setEncoding('base64')
+            for await (const chunk of val) {
+              yield chunk
+            }
+
+            yield '"'
+          } else {
+            yield JSON.stringify(val)
+          }
+        }
+        yield '}'
+      }
+
+      yield ']'
+    }
+
     // Include this.values for placeholders
     /** @type {unknown[][]} */
-    this.entries = [[...this.values, JSON.stringify(INSERT.entries)]]
-    return (this.sql = `INSERT INTO ${this.quote(entity)}${alias ? ' as ' + this.quote(alias) : ''} (${
-      this.columns
-    }) SELECT ${extraction} FROM json_each(?)`)
+    this.entries = [[...this.values,
+    INSERT.entries instanceof Readable
+      ? INSERT.entries
+      : Readable.from(stringify(INSERT.entries))
+    ]]
+    return (this.sql = `INSERT INTO ${this.quote(entity)}${alias ? ' as ' + this.quote(alias) : ''} (${this.columns
+      }) SELECT ${extraction} FROM json_each(?)`)
   }
 
   /**
diff --git a/sqlite/test/general/stream.test.js b/sqlite/test/general/stream.test.js
index fb883167b..473ab64c4 100644
--- a/sqlite/test/general/stream.test.js
+++ b/sqlite/test/general/stream.test.js
@@ -21,11 +21,11 @@ describe('STREAM', () => {
 
   describe('cds.stream', () => {
     beforeAll(async () => {
-      const data = fs.readFileSync(path.join(__dirname, 'samples/test.jpg'))
-      await cds.run('INSERT INTO test_Images values(?,?)', [
-        [1, data],
-        [2, null],
-      ])
+      let data = fs.createReadStream(path.join(__dirname, 'samples/test.jpg'))
+      await INSERT([
+        { data: data, ID: 1 },
+        { data: null, ID: 2 },
+      ]).into('test.Images')
     })
 
     afterAll(async () => {
@@ -236,7 +236,7 @@ describe('STREAM', () => {
         const { Images } = cds.entities('test')
         const stream = fs.createReadStream(path.join(__dirname, 'samples/data.json'))
 
-        const changes = await STREAM.into(Images).data(stream)
+        const changes = await INSERT.into(Images).entries(stream)
         try {
           expect(changes).toEqual(2)
         } catch (e) {
@@ -246,7 +246,7 @@ describe('STREAM', () => {
         const out1000 = fs.createWriteStream(path.join(__dirname, 'samples/1000.png'))
         const out1001 = fs.createWriteStream(path.join(__dirname, 'samples/1001.png'))
 
-        const in1000 = await STREAM.from(Images, { ID: 1000 }).column('data')
+        const in1000 = (await SELECT.one.from(Images, { ID: 1000 }).columns('data')).data
         const in1001 = await STREAM.from(Images, { ID: 1001 }).column('data')
 
         in1000.pipe(out1000)

From 236d17a4c2dbd328502d1b4292489e364e3ed164 Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Wed, 15 Nov 2023 14:02:10 +0100
Subject: [PATCH 02/10] Adjust HANA to new entries stream logic

---
 db-service/lib/cqn2sql.js          | 86 +++++++++++++++---------------
 hana/lib/HANAService.js            |  8 ++-
 sqlite/test/general/stream.test.js |  2 +-
 3 files changed, 50 insertions(+), 46 deletions(-)

diff --git a/db-service/lib/cqn2sql.js b/db-service/lib/cqn2sql.js
index 0b6ee9f1d..5ffcdabb3 100644
--- a/db-service/lib/cqn2sql.js
+++ b/db-service/lib/cqn2sql.js
@@ -423,57 +423,57 @@ class CQN2SQLRenderer {
       .filter(a => a)
       .map(c => c.sql)
 
-    // REVISIT: yield less often
-    const stringify = async function* (entries) {
-      yield '['
-
-      let sep = ''
-      for (const row of entries) {
-        if (!sep) sep = ','
-        else yield sep
-
-        let sepsub = ''
-        yield '{'
-        for (const key in row) {
-
-          if (!sepsub) sepsub = ','
-          else yield sepsub
-
-          yield JSON.stringify(key)
-          yield ':'
-
-          const val = row[key]
-          if (val instanceof Readable) {
-            yield '"'
-
-            // TODO: double check that it works
-            val.setEncoding('base64')
-            for await (const chunk of val) {
-              yield chunk
-            }
-
-            yield '"'
-          } else {
-            yield JSON.stringify(val)
-          }
-        }
-        yield '}'
-      }
-
-      yield ']'
-    }
-
     // Include this.values for placeholders
     /** @type {unknown[][]} */
     this.entries = [[...this.values,
-    INSERT.entries instanceof Readable
-      ? INSERT.entries
-      : Readable.from(stringify(INSERT.entries))
+    INSERT.entries[0] instanceof Readable
+      ? INSERT.entries[0]
+      : Readable.from(this.INSERT_entries_stream(INSERT.entries))
     ]]
     return (this.sql = `INSERT INTO ${this.quote(entity)}${alias ? ' as ' + this.quote(alias) : ''} (${this.columns
       }) SELECT ${extraction} FROM json_each(?)`)
   }
 
+  // REVISIT: yield less often
+  async *INSERT_entries_stream(entries) {
+    yield '['
+
+    let sep = ''
+    for (const row of entries) {
+      if (!sep) sep = ','
+      else yield sep
+
+      let sepsub = ''
+      yield '{'
+      for (const key in row) {
+
+        if (!sepsub) sepsub = ','
+        else yield sepsub
+
+        yield JSON.stringify(key)
+        yield ':'
+
+        const val = row[key]
+        if (val instanceof Readable) {
+          yield '"'
+
+          // TODO: double check that it works
+          val.setEncoding('base64')
+          for await (const chunk of val) {
+            yield chunk
+          }
+
+          yield '"'
+        } else {
+          yield JSON.stringify(val)
+        }
+      }
+      yield '}'
+    }
+
+    yield ']'
+  }
+
   /**
    * Renders an INSERT query with rows property
    * @param {import('./infer/cqn').INSERT} q
diff --git a/hana/lib/HANAService.js b/hana/lib/HANAService.js
index 0212a9b42..5b77a80b8 100644
--- a/hana/lib/HANAService.js
+++ b/hana/lib/HANAService.js
@@ -95,7 +95,7 @@ class HANAService extends SQLService {
     if (!sql) return // Do nothing when there is nothing to be done
     const ps = await this.prepare(sql)
     // HANA driver supports batch execution
-    const results = entries ? await ps.runBatch(entries) : await ps.run()
+    const results = entries ? await ps.run(entries) : await ps.run()
     return new this.class.InsertResults(cqn, results)
   }
 
@@ -570,7 +570,11 @@ class HANAService extends SQLService {
           })
         cur[0] += ']'
       } else {
-        this.entries = [[JSON.stringify(INSERT.entries)]]
+        this.entries = [
+          INSERT.entries[0] instanceof Readable
+            ? INSERT.entries[0]
+            : Readable.from(this.INSERT_entries_stream(INSERT.entries))
+          ]
       }
 
       // WITH SRC is used to force HANA to interpret the ? as a NCLOB allowing for streaming of the data
diff --git a/sqlite/test/general/stream.test.js b/sqlite/test/general/stream.test.js
index 473ab64c4..70e420879 100644
--- a/sqlite/test/general/stream.test.js
+++ b/sqlite/test/general/stream.test.js
@@ -246,7 +246,7 @@ describe('STREAM', () => {
         const out1000 = fs.createWriteStream(path.join(__dirname, 'samples/1000.png'))
         const out1001 = fs.createWriteStream(path.join(__dirname, 'samples/1001.png'))
 
-        const in1000 = (await SELECT.one.from(Images, { ID: 1000 }).columns('data')).data
+        const in1000 = await STREAM.from(Images, { ID: 1000 }).column('data')
         const in1001 = await STREAM.from(Images, { ID: 1001 }).column('data')
 
         in1000.pipe(out1000)

From 6a867c0f05f5e8b878cf05ce7a905d28812ae8da Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Thu, 16 Nov 2023 10:43:39 +0100
Subject: [PATCH 03/10] Adjust HANAService for HANA SP2

---
 hana/lib/HANAService.js | 34 +++++++---------------------------
 1 file changed, 7 insertions(+), 27 deletions(-)

diff --git a/hana/lib/HANAService.js b/hana/lib/HANAService.js
index 5b77a80b8..a1f69cfa5 100644
--- a/hana/lib/HANAService.js
+++ b/hana/lib/HANAService.js
@@ -86,16 +86,15 @@ class HANAService extends SQLService {
   }
 
   async onINSERT({ query, data }) {
-    // Using runBatch for HANA 2.0 and lower sometimes leads to integer underflow errors
-    // REVISIT: Address runBatch issues in node-hdb and hana-client
-    if (HANAVERSION <= 2) {
-      return super.onINSERT(...arguments)
-    }
     const { sql, entries, cqn } = this.cqn2sql(query, data)
     if (!sql) return // Do nothing when there is nothing to be done
     const ps = await this.prepare(sql)
     // HANA driver supports batch execution
-    const results = entries ? await ps.run(entries) : await ps.run()
+    const results = await (entries
+      ? HANAVERSION <= 2
+        ? entries.reduce((l, c) => l.then(() => ps.run(c)), Promise.resolve(0))
+        : ps.run(entries)
+      : ps.run())
     return new this.class.InsertResults(cqn, results)
   }
 
@@ -549,32 +548,13 @@ class HANAService extends SQLService {
       // HANA Express does not process large JSON documents
       // The limit is somewhere between 64KB and 128KB
       if (HANAVERSION <= 2) {
-        // Simple line splitting would be preferred, but batch execute does not work properly
-        // Which makes sending every line separately much slower
-        // this.entries = INSERT.entries.map(e => [JSON.stringify(e)])
-
-        this.entries = []
-        let cur = ['[']
-        this.entries.push(cur)
-        INSERT.entries
-          .map(r => JSON.stringify(r))
-          .forEach(r => {
-            if (cur[0].length > 65535) {
-              cur[0] += ']'
-              cur = ['[']
-              this.entries.push(cur)
-            } else if (cur[0].length > 1) {
-              cur[0] += ','
-            }
-            cur[0] += r
-          })
-        cur[0] += ']'
+        this.entries = INSERT.entries.map(e => (e instanceof Readable ? [e] : [Readable.from(this.INSERT_entries_stream([e]))]))
       } else {
         this.entries = [
           INSERT.entries[0] instanceof Readable
             ? INSERT.entries[0]
             : Readable.from(this.INSERT_entries_stream(INSERT.entries))
-          ]
+        ]
       }
 
       // WITH SRC is used to force HANA to interpret the ? as a NCLOB allowing for streaming of the data

From f5793c59d1067137a3680eaddceed5b9947b8f07 Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Tue, 21 Nov 2023 11:30:49 +0100
Subject: [PATCH 04/10] Align rows with entries and test expectations

---
 db-service/lib/cqn2sql.js              | 57 ++++++++++++++++++++++----
 db-service/test/cqn2sql/insert.test.js | 22 +++++-----
 db-service/test/cqn2sql/upsert.test.js | 14 ++++---
 3 files changed, 70 insertions(+), 23 deletions(-)

diff --git a/db-service/lib/cqn2sql.js b/db-service/lib/cqn2sql.js
index 5ffcdabb3..a9068d54c 100644
--- a/db-service/lib/cqn2sql.js
+++ b/db-service/lib/cqn2sql.js
@@ -465,7 +465,7 @@ class CQN2SQLRenderer {
 
           yield '"'
         } else {
-          yield JSON.stringify(val)
+          yield val === undefined ? 'null' : JSON.stringify(val)
         }
       }
       yield '}'
@@ -474,6 +474,43 @@ class CQN2SQLRenderer {
     yield ']'
   }
 
+  // REVISIT: yield less often
+  async *INSERT_rows_stream(entries) {
+    yield '['
+
+    let sep = ''
+    for (const row of entries) {
+      if (!sep) sep = ','
+      else yield sep
+
+      let sepsub = ''
+      yield '['
+      for (let key = 0; key < row.length; key++) {
+
+        if (!sepsub) sepsub = ','
+        else yield sepsub
+
+        const val = row[key]
+        if (val instanceof Readable) {
+          yield '"'
+
+          // TODO: double check that it works
+          val.setEncoding('base64')
+          for await (const chunk of val) {
+            yield chunk
+          }
+
+          yield '"'
+        } else {
+          yield val === undefined ? 'null' : JSON.stringify(val)
+        }
+      }
+      yield ']'
+    }
+
+    yield ']'
+  }
+
   /**
    * Renders an INSERT query with rows property
    * @param {import('./infer/cqn').INSERT} q
@@ -485,21 +522,27 @@ class CQN2SQLRenderer {
     const alias = INSERT.into.as
     const elements = q.elements || q.target?.elements
     const columns = INSERT.columns
-    || cds.error`Cannot insert rows without columns or elements`
+      || cds.error`Cannot insert rows without columns or elements`
 
     const inputConverter = this.class._convertInput
-    const extraction = columns.map((c,i) => {
+    const extraction = columns.map((c, i) => {
       const extract = `value->>'$[${i}]'`
       const element = elements?.[c]
       const converter = element?.[inputConverter]
-      return converter?.(extract,element) || extract
+      return converter?.(extract, element) || extract
     })
 
     this.columns = columns.map(c => this.quote(c))
     this.entries = [[JSON.stringify(INSERT.rows)]]
-    return (this.sql = `INSERT INTO ${this.quote(entity)}${alias ? ' as ' + this.quote(alias) : ''} (${
-      this.columns
-    }) SELECT ${extraction} FROM json_each(?)`)
+
+    this.entries = [[...this.values,
+    INSERT.rows instanceof Readable
+      ? INSERT.rows
+      : Readable.from(this.INSERT_rows_stream(INSERT.rows))
+    ]]
+
+    return (this.sql = `INSERT INTO ${this.quote(entity)}${alias ? ' as ' + this.quote(alias) : ''} (${this.columns
+      }) SELECT ${extraction} FROM json_each(?)`)
   }
 
   /**
diff --git a/db-service/test/cqn2sql/insert.test.js b/db-service/test/cqn2sql/insert.test.js
index d151ccdc7..40a7ff0ac 100644
--- a/db-service/test/cqn2sql/insert.test.js
+++ b/db-service/test/cqn2sql/insert.test.js
@@ -1,4 +1,6 @@
 'use strict'
+const { text } = require('stream/consumers')
+
 const cds = require('@sap/cds/lib')
 const cqn2sql = require('../../lib/cqn2sql')
 
@@ -9,7 +11,7 @@ beforeAll(async () => {
 describe('insert', () => {
   describe('insert only', () => {
     // Values are missing
-    test('test with insert values into columns', () => {
+    test('test with insert values into columns', async () => {
       const cqnInsert = {
         INSERT: {
           into: { ref: ['Foo'] },
@@ -19,10 +21,10 @@ describe('insert', () => {
       }
 
       const { sql, entries } = cqn2sql(cqnInsert)
-      expect({ sql, entries }).toMatchSnapshot()
+      expect({ sql, entries: [[await text(entries[0][0])]] }).toMatchSnapshot()
     })
 
-    test('test with insert rows into columns', () => {
+    test('test with insert rows into columns', async () => {
       const cqnInsert = {
         INSERT: {
           into: { ref: ['Foo'] },
@@ -34,11 +36,11 @@ describe('insert', () => {
         },
       }
       const { sql, entries } = cqn2sql(cqnInsert)
-      expect({ sql, entries }).toMatchSnapshot()
+      expect({ sql, entries: [[await text(entries[0][0])]] }).toMatchSnapshot()
     })
 
     // no filtering in INSERT
-    xtest('test filter in insert rows into columns with not existing column', () => {
+    xtest('test filter in insert rows into columns with not existing column', async () => {
       const cqnInsert = {
         INSERT: {
           into: { ref: ['Foo2'] },
@@ -50,10 +52,10 @@ describe('insert', () => {
         },
       }
       const { sql, entries } = cqn2sql(cqnInsert)
-      expect({ sql, entries }).toMatchSnapshot()
+      expect({ sql, entries: [[await text(entries[0][0])]] }).toMatchSnapshot()
     })
 
-    test('test with insert entries', () => {
+    test('test with insert entries', async () => {
       const cqnInsert = {
         INSERT: {
           into: 'Foo2',
@@ -65,10 +67,10 @@ describe('insert', () => {
       }
 
       const { sql, entries } = cqn2sql(cqnInsert)
-      expect({ sql, entries }).toMatchSnapshot()
+      expect({ sql, entries: [[await text(entries[0][0])]] }).toMatchSnapshot()
     })
 
-    test('test with insert with alias', () => {
+    test('test with insert with alias', async () => {
       const cqnInsert = {
         INSERT: {
           into: { ref: ['Foo2'], as: 'Fooooo2' },
@@ -80,7 +82,7 @@ describe('insert', () => {
       }
 
       const { sql, entries } = cqn2sql(cqnInsert)
-      expect({ sql, entries }).toMatchSnapshot()
+      expect({ sql, entries: [[await text(entries[0][0])]] }).toMatchSnapshot()
     })
   })
 
diff --git a/db-service/test/cqn2sql/upsert.test.js b/db-service/test/cqn2sql/upsert.test.js
index df6b0c18b..4e929493f 100644
--- a/db-service/test/cqn2sql/upsert.test.js
+++ b/db-service/test/cqn2sql/upsert.test.js
@@ -1,4 +1,6 @@
 'use strict'
+const { text } = require('stream/consumers')
+
 const cds = require('@sap/cds/lib')
 const cqn2sql = require('../../lib/cqn2sql')
 
@@ -7,7 +9,7 @@ beforeAll(async () => {
 })
 
 describe('upsert', () => {
-  test('test with keys only', () => {
+  test('test with keys only', async () => {
     const cqnUpsert = {
       UPSERT: {
         into: 'Foo2',
@@ -17,11 +19,11 @@ describe('upsert', () => {
     }
 
     const { sql, entries } = cqn2sql(cqnUpsert)
-    expect({ sql, entries }).toMatchSnapshot()
+    expect({ sql, entries:  [[await text(entries[0][0])]] }).toMatchSnapshot()
   })
 
-  test('test with entries', () => {
-    const cqnInsert = {
+  test('test with entries', async () => {
+    const cqnUpsert = {
       UPSERT: {
         into: 'Foo2',
         entries: [
@@ -31,7 +33,7 @@ describe('upsert', () => {
       },
     }
 
-    const { sql, entries } = cqn2sql(cqnInsert)
-    expect({ sql, entries }).toMatchSnapshot()
+    const { sql, entries } = cqn2sql(cqnUpsert)
+    expect({ sql, entries: [[await text(entries[0][0])]] }).toMatchSnapshot()
   })
 })

From 83a123922f67eb88742640fdcf665ec07154dcfe Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Tue, 21 Nov 2023 14:51:10 +0100
Subject: [PATCH 05/10] Reduce number of yield calls

---
 db-service/lib/cqn2sql.js | 68 ++++++++++++++++++++++-----------------
 1 file changed, 39 insertions(+), 29 deletions(-)

diff --git a/db-service/lib/cqn2sql.js b/db-service/lib/cqn2sql.js
index 5f43c5540..82bec2cfa 100644
--- a/db-service/lib/cqn2sql.js
+++ b/db-service/lib/cqn2sql.js
@@ -434,81 +434,91 @@ class CQN2SQLRenderer {
       }) SELECT ${extraction} FROM json_each(?)`)
   }
 
-  // REVISIT: yield less often
   async *INSERT_entries_stream(entries) {
-    yield '['
+    const bufferLimit = 1 << 16
+    let buffer = '['
 
     let sep = ''
     for (const row of entries) {
+      buffer += `${sep}{`
       if (!sep) sep = ','
-      else yield sep
 
       let sepsub = ''
-      yield '{'
       for (const key in row) {
-
+        const keyJSON = `${sepsub}${JSON.stringify(key)}:`
         if (!sepsub) sepsub = ','
-        else yield sepsub
-
-        yield JSON.stringify(key)
-        yield ':'
 
         const val = row[key]
         if (val instanceof Readable) {
-          yield '"'
+          buffer += `${keyJSON}"`
 
           // TODO: double check that it works
           val.setEncoding('base64')
           for await (const chunk of val) {
-            yield chunk
+            buffer += chunk
+            if (buffer.length > bufferLimit) {
+              yield buffer
+              buffer = ''
+            }
           }
 
-          yield '"'
+          buffer += '"'
         } else {
-          yield val === undefined ? 'null' : JSON.stringify(val)
+          buffer += `${keyJSON}${val === undefined ? 'null' : JSON.stringify(val)}`
         }
       }
-      yield '}'
+      buffer += '}'
+      if (buffer.length > bufferLimit) {
+        yield buffer
+        buffer = ''
+      }
     }
 
-    yield ']'
+    buffer += ']'
+    yield buffer
   }
 
-  // REVISIT: yield less often
   async *INSERT_rows_stream(entries) {
-    yield '['
+    const bufferLimit = 1 << 16
+    let buffer = '['
 
     let sep = ''
     for (const row of entries) {
+      buffer += `${sep}[`
       if (!sep) sep = ','
-      else yield sep
 
       let sepsub = ''
-      yield '['
       for (let key = 0; key < row.length; key++) {
-
-        if (!sepsub) sepsub = ','
-        else yield sepsub
-
         const val = row[key]
         if (val instanceof Readable) {
-          yield '"'
+          buffer += `${sepsub}"`
 
           // TODO: double check that it works
           val.setEncoding('base64')
           for await (const chunk of val) {
-            yield chunk
+            buffer += chunk
+            if (buffer.length > bufferLimit) {
+              yield buffer
+              buffer = ''
+            }
           }
 
-          yield '"'
+          buffer += '"'
         } else {
-          yield val === undefined ? 'null' : JSON.stringify(val)
+          buffer += `${sepsub}${val === undefined ? 'null' : JSON.stringify(val)}`
         }
+
+        if (!sepsub) sepsub = ','
+      }
+      buffer += ']'
+      if (buffer.length > bufferLimit) {
+        yield buffer
+        buffer = ''
       }
-      yield ']'
     }
 
-    yield ']'
+    buffer += ']'
+    yield buffer
   }
 
   /**

From 99cec018826c65d5f924502c41b13e74c01b4d8e Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Fri, 1 Dec 2023 10:05:32 +0100
Subject: [PATCH 06/10] Adjust entries stream for postgres

---
 db-service/lib/cqn2sql.js       | 29 ++++++++++++++++++-----------
 postgres/lib/PostgresService.js |  9 +++++----
 2 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/db-service/lib/cqn2sql.js b/db-service/lib/cqn2sql.js
index 929bedda8..78190f1fe 100644
--- a/db-service/lib/cqn2sql.js
+++ b/db-service/lib/cqn2sql.js
@@ -426,11 +426,16 @@ class CQN2SQLRenderer {
 
     // Include this.values for placeholders
     /** @type {unknown[][]} */
-    this.entries = [[...this.values,
-    INSERT.entries[0] instanceof Readable
-      ? INSERT.entries[0]
-      : Readable.from(this.INSERT_entries_stream(INSERT.entries))
-    ]]
+    this.entries = []
+    if (INSERT.entries[0] instanceof Readable) {
+      INSERT.entries[0].type = 'json'
+      this.entries = [[...this.values, INSERT.entries[0]]]
+    } else {
+      const stream = Readable.from(this.INSERT_entries_stream(INSERT.entries))
+      stream.type = 'json'
+      this.entries = [[...this.values, stream]]
+    }
+
     return (this.sql = `INSERT INTO ${this.quote(entity)}${alias ? ' as ' + this.quote(alias) : ''} (${this.columns
       }) SELECT ${extraction} FROM json_each(?)`)
   }
@@ -544,13 +549,15 @@ class CQN2SQLRenderer {
     })
 
     this.columns = columns.map(c => this.quote(c))
-    this.entries = [[JSON.stringify(INSERT.rows)]]
 
-    this.entries = [[...this.values,
-    INSERT.rows instanceof Readable
-      ? INSERT.rows
-      : Readable.from(this.INSERT_rows_stream(INSERT.rows))
-    ]]
+    if (INSERT.rows[0] instanceof Readable) {
+      INSERT.rows[0].type = 'json'
+      this.entries = [[...this.values, INSERT.rows[0]]]
+    } else {
+      const stream = Readable.from(this.INSERT_rows_stream(INSERT.rows))
+      stream.type = 'json'
+      this.entries = [[...this.values, stream]]
+    }
 
     return (this.sql = `INSERT INTO ${this.quote(entity)}${alias ? ' as ' + this.quote(alias) : ''} (${this.columns
       }) SELECT ${extraction} FROM json_each(?)`)
diff --git a/postgres/lib/PostgresService.js b/postgres/lib/PostgresService.js
index 424d32a08..051c86bc5 100644
--- a/postgres/lib/PostgresService.js
+++ b/postgres/lib/PostgresService.js
@@ -135,12 +135,13 @@ GROUP BY k
   }
 
   prepare(sql) {
-    const query = {
+    // Track queries name for postgres referencing prepare statements
+    // sha1 as it needs to be less then 63 character
+    const sha = crypto.createHash('sha1').update(sql).digest('hex')
+    const query = this._queryCache[sha] = this._queryCache[sha] || {
       _streams: 0,
       text: sql,
-      // Track queries name for postgres referencing prepare statements
-      // sha1 as it needs to be less then 63 characters
-      name: crypto.createHash('sha1').update(sql).digest('hex'),
+      name: sha,
     }
     return {
       run: async values => {

From 2a689dcf94bec5bae15f80a022c80dcaa5395765 Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Fri, 1 Dec 2023 10:15:35 +0100
Subject: [PATCH 07/10] Add missing cache initialization

---
 postgres/lib/PostgresService.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/postgres/lib/PostgresService.js b/postgres/lib/PostgresService.js
index 051c86bc5..cdbd8091b 100644
--- a/postgres/lib/PostgresService.js
+++ b/postgres/lib/PostgresService.js
@@ -13,6 +13,7 @@ class PostgresService extends SQLService {
       cds.options.dialect = 'postgres'
     }
     this.kind = 'postgres'
+    this._queryCache = {}
     return super.init(...arguments)
   }
 

From c46eba45e7fb4bb332874fd422cabb02a5863ca0 Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Mon, 4 Dec 2023 10:28:00 +0100
Subject: [PATCH 08/10] Add sort to genres read after write test

---
 test/scenarios/bookshop/genres.test.js | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/test/scenarios/bookshop/genres.test.js b/test/scenarios/bookshop/genres.test.js
index eba388dac..d421b918f 100644
--- a/test/scenarios/bookshop/genres.test.js
+++ b/test/scenarios/bookshop/genres.test.js
@@ -35,6 +35,17 @@ describe('Bookshop - Genres', () => {
 
     delete insertResponse.data['@odata.context']
     const assert = require('assert')
+
+    // Read after write does not sort the results
+    // therefor asynchronious databases might return in different orders
+    const sort = (a, b) => {
+      if (!b?.children) return
+      const order = b.children.reduce((l, c, i) => { l[c.ID] = i; return l }, {})
+      b.children.sort((a, b) => order[a.ID] - order[b.ID])
+      b.children.forEach((c, i) => sort(c, a.children[i]))
+    }
+
+    sort(insertResponse.data, body)
     assert.deepEqual(insertResponse.data, body)
 
     // REVISIT clean up so the deep update test does not fail

From 8f6dfc17223a3c14a1491a5d22e7e974259a50b7 Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Mon, 4 Dec 2023 10:37:52 +0100
Subject: [PATCH 09/10] Adjust sort relation

---
 test/scenarios/bookshop/update.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/scenarios/bookshop/update.test.js b/test/scenarios/bookshop/update.test.js
index 28fdcd9ff..d9eeb7151 100644
--- a/test/scenarios/bookshop/update.test.js
+++ b/test/scenarios/bookshop/update.test.js
@@ -54,7 +54,7 @@ describe('Bookshop - Update', () => {
     expect(affectedRows).to.be.eq(0)
   })
 
-  test('Update with path expressions', async () => {
+  xtest('Update with path expressions', async () => {
     const updateRichardsBooks = UPDATE.entity('AdminService.RenameKeys')
       .where(`author.name = 'Richard Carpenter'`)
       .set('ID = 42')

From 2b25b8c0de6ef7df26a3996884d701fc54dcee9d Mon Sep 17 00:00:00 2001
From: Bob den Os <bob.den.os@sap.com>
Date: Mon, 4 Dec 2023 12:01:39 +0100
Subject: [PATCH 10/10] Adjust sort relation

---
 test/scenarios/bookshop/genres.test.js | 6 +++---
 test/scenarios/bookshop/update.test.js | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/scenarios/bookshop/genres.test.js b/test/scenarios/bookshop/genres.test.js
index d421b918f..a644caf0f 100644
--- a/test/scenarios/bookshop/genres.test.js
+++ b/test/scenarios/bookshop/genres.test.js
@@ -39,10 +39,10 @@ describe('Bookshop - Genres', () => {
     // Read after write does not sort the results
     // therefor asynchronious databases might return in different orders
     const sort = (a, b) => {
-      if (!b?.children) return
+      if (!a?.children || !b?.children) return
       const order = b.children.reduce((l, c, i) => { l[c.ID] = i; return l }, {})
-      b.children.sort((a, b) => order[a.ID] - order[b.ID])
-      b.children.forEach((c, i) => sort(c, a.children[i]))
+      a.children.sort((a, b) => order[a.ID] - order[b.ID])
+      a.children.forEach((c, i) => sort(c, b.children[i]))
     }
 
     sort(insertResponse.data, body)
diff --git a/test/scenarios/bookshop/update.test.js b/test/scenarios/bookshop/update.test.js
index d9eeb7151..28fdcd9ff 100644
--- a/test/scenarios/bookshop/update.test.js
+++ b/test/scenarios/bookshop/update.test.js
@@ -54,7 +54,7 @@ describe('Bookshop - Update', () => {
     expect(affectedRows).to.be.eq(0)
   })
 
-  xtest('Update with path expressions', async () => {
+  test('Update with path expressions', async () => {
     const updateRichardsBooks = UPDATE.entity('AdminService.RenameKeys')
       .where(`author.name = 'Richard Carpenter'`)
       .set('ID = 42')