diff --git a/ci/migration/README.md b/ci/migration/README.md
new file mode 100644
index 0000000000..2765d1f2b1
--- /dev/null
+++ b/ci/migration/README.md
@@ -0,0 +1,261 @@
+# Cross‑Platform ODBC DSN Migration Scripts (Windows / Linux / macOS)
+
+This repository provides **cross‑platform migration scripts** to move existing
+BigQuery ODBC DSNs from legacy **Simba drivers** to the new **ODBC Driver for
+BigQuery**.
+
+The scripts support:
+
+- **Windows** (PowerShell)
+- **Linux** (Bash)
+- **macOS** (Bash)
+
+They follow the **same high‑level behavior and migration semantics** across all
+platforms, with platform‑specific implementation details.
+
+______________________________________________________________________
+
+## Goals of the Migration
+
+- Seamlessly transition DSNs from Simba BigQuery drivers to the Google‑provided
+  ODBC Driver for BigQuery
+- Preserve existing DSN configuration wherever possible
+- Support **safe testing (copy mode)** and **in‑place migration (replace mode)**
+- Minimize manual registry / config file editing
+
+______________________________________________________________________
+
+## What the Script Does
+
+At a high level, the script performs the following steps:
+
+1. **Installs the new ODBC Driver for BigQuery** .
+2. **Searches for existing DSNs** that use the legacy Simba BigQuery driver.
+3. **Prompts the user to select a DSN** if multiple Simba-based DSNs are found.
+4. **Migrates the selected DSN** based on the chosen migration mode (`copy` or
+   `replace`).
+5. **Updates registry entries for Windows** so the DSN points to the new Google
+   BigQuery ODBC driver.
+6. **Decrypts and migrates encrypted credentials** (if present).
+7. **Tests the migrated DSN connection** at the end.
+
+______________________________________________________________________
+
+## Supported Drivers
+
+| Platform      | Legacy Driver Detected                | Target Driver            |
+| ------------- | ------------------------------------- | ------------------------ |
+| Windows       | Simba ODBC Driver for Google BigQuery | ODBC Driver for BigQuery |
+| Linux / macOS | Simba Google BigQuery ODBC Connector  | ODBC Driver for BigQuery |
+
+______________________________________________________________________
+
+## Migration Modes (All Platforms)
+
+Both scripts support the same two explicit modes.
+
+### 1. `copy` Mode (Recommended for first run)
+
+**Behavior:**
+
+- Original Simba DSN is **left unchanged**
+- A **new DSN is created** using the Google driver
+- New DSN name is derived automatically
+
+| Original DSN | New DSN                        |
+| ------------ | ------------------------------ |
+| `MyBQDSN`    | `MyBQDSN_Google` (Windows)     |
+| `MyBQDSN`    | `MyBQDSN_google` (Linux/macOS) |
+
+**Use this when:**
+
+- You want side‑by‑side validation
+- You need a rollback path
+- Applications may still depend on the old DSN
+
+______________________________________________________________________
+
+### 2. `replace` Mode (In‑place migration)
+
+**Behavior:**
+
+- DSN name remains **unchanged**
+- Driver reference and configuration are updated **in place**
+- Applications do not need configuration changes
+
+**Use this when:**
+
+- You are confident in the new driver
+- DSN names must remain stable
+
+______________________________________________________________________
+
+## When the Scripts Prompt for a DSN
+
+### Common Logic (All Platforms)
+
+The scripts first discover **all DSNs that use a Simba BigQuery driver**.
+
+There are three possible scenarios:
+
+______________________________________________________________________
+
+### Scenario A: No Simba DSNs Found
+
+- Message is printed indicating no migration is needed
+- Script exits safely without making changes
+
+______________________________________________________________________
+
+### Scenario B: Exactly One Simba DSN Found
+
+- That DSN is **automatically selected**
+- **No prompt** is shown
+- Migration proceeds immediately
+
+______________________________________________________________________
+
+### Scenario C: Multiple Simba DSNs Found
+
+- The script **lists all matching DSNs**
+- The user is **prompted to select exactly one DSN** to migrate
+
+```text
+Multiple Simba DSNs found:
+ [1] FinanceBQ
+ [2] AnalyticsBQ
+
+Enter the number of the DSN you want to migrate:
+```
+
+- Migration continues only after a valid selection
+- Only the selected DSN is migrated.
+
+This prevents accidental bulk or unintended migrations.
+
+______________________________________________________________________
+
+## Platform‑Specific Details
+
+## Windows (PowerShell)
+
+### Script
+
+```
+migrate.ps1
+```
+
+### Usage
+
+```
+migrate.ps1 -Mode copy    -DriverInstaller GoogleBigQueryODBC.msi
+migrate.ps1 -Mode replace -DriverInstaller GoogleBigQueryODBC.msi
+```
+
+### DSN Discovery
+
+- System DSNs: `HKLM\\SOFTWARE\\ODBC\\ODBC.INI`
+- User DSNs: `HKCU\\SOFTWARE\\ODBC\\ODBC.INI`
+
+### Windows‑Specific Behavior
+
+- Installs the driver via **silent MSI** (`msiexec /quiet`)
+- Copies DSN registry trees
+- Updates `Driver` and `TrustedCerts` paths
+- Decrypts `KeyFilePath_Enc` using **Windows DPAPI**
+- Automatically tests the migrated DSN connection
+
+> ⚠️ Run from an **elevated PowerShell prompt** when migrating system DSNs.
+
+______________________________________________________________________
+
+## Linux / macOS (Bash)
+
+### Script
+
+```
+migrate.sh
+```
+
+### Usage
+
+```
+./migrate.sh copy    <installer-dir|zip|tar.gz>
+./migrate.sh replace <installer-dir|zip|tar.gz>
+```
+
+### Installer Input
+
+The installer argument may be:
+
+- A directory
+- `.zip`
+- `.tar.gz` / `.tgz`
+
+The script automatically extracts and locates the driver library.
+
+### DSN Discovery
+
+- Uses `odbc.ini`
+
+- Resolution order:
+
+  1. `$ODBCINI` environment variable (if set)
+  2. `/etc/odbc.ini`
+
+### Linux/macOS‑Specific Behavior
+
+- Copies driver to:
+
+  ```
+  /usr/local/lib/google_odbc
+  ```
+
+- Creates a timestamped backup of `odbc.ini`
+
+- Updates:
+
+  - `[ODBC Data Sources]`
+  - Individual DSN sections
+
+- Uses `sudo` automatically when required
+
+______________________________________________________________________
+
+## Configuration Files Modified
+
+| Platform    | Configuration                     |
+| ----------- | --------------------------------- |
+| Windows     | Registry (ODBC.INI, ODBCINST.INI) |
+| Linux/macOS | `odbc.ini`                        |
+
+All scripts create backups before modifying configuration.
+
+______________________________________________________________________
+
+## Safety & Best Practices
+
+- **Start with `copy` mode** on all platforms
+- Validate applications against the new DSN
+- Keep backups until rollout is complete
+- Use `replace` only when DSN names must remain unchanged
+
+______________________________________________________________________
+
+## Summary Table
+
+| Feature             | Windows             | Linux/macOS                 |
+| ------------------- | ------------------- | --------------------------- |
+| Script              | PowerShell          | Bash                        |
+| DSN store           | Registry            | odbc.ini                    |
+| Installer           | MSI                 | dir / zip / tar.gz          |
+| Copy mode           | `<DSN>_Google`      | `<DSN>_google`              |
+| Replace mode        | In‑place            | In‑place                    |
+| Multi‑DSN prompt    | Yes                 | Yes                         |
+| Backup created      | Implicit (registry) | Explicit `.bak.<timestamp>` |
+| Credential handling | DPAPI decrypt       | Plain‑text only             |
+
+______________________________________________________________________
+
+This unified behavior ensures a **predictable, safe migration experience across
+Windows, Linux, and macOS**.
diff --git a/ci/migration/migrate_dsn.ps1 b/ci/migration/migrate_dsn.ps1
new file mode 100644
index 0000000000..a5477cb2b8
--- /dev/null
+++ b/ci/migration/migrate_dsn.ps1
@@ -0,0 +1,225 @@
+# !/usr/bin/env powershell
+#
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+<#
+Migration script for Windows ODBC DSNs
+- Migrates from "Simba ODBC Driver for Google Bigquery"
+- to       "ODBC Driver for BigQuery"
+
+Usage:
+    migrate.ps1 -Mode copy -DriverInstaller "GoogleBigQueryODBC.msi"
+    migrate.ps1 -Mode replace -DriverInstaller "GoogleBigQueryODBC.msi"
+#>
+
+param(
+    [Parameter(Mandatory=$true)]
+    [ValidateSet("copy","replace")]
+    [string]$Mode,
+
+    [Parameter(Mandatory=$true)]
+    [string]$DriverInstaller
+)
+
+$SimbaDriverName  = "Simba ODBC Driver for Google Bigquery"
+$GoogleDriverName = "ODBC Driver for BigQuery"
+
+Write-Host "=== Installing ODBC Driver for BigQuery ==="
+Start-Process "msiexec.exe" -ArgumentList "/i `"$DriverInstaller`" /quiet /norestart" -Wait
+Write-Host "=== Driver installation complete ===`n"
+
+# Registry paths for DSNs
+$DSNRoots = @(
+    "HKLM:\SOFTWARE\ODBC\ODBC.INI",
+    "HKCU:\SOFTWARE\ODBC\ODBC.INI"
+)
+$DSNListRoot = "ODBC Data Sources"
+
+function CopyRegistryTree($SourcePath, $TargetPath) {
+    if (!(Test-Path $TargetPath)) {
+        New-Item -Path $TargetPath | Out-Null
+    }
+
+    $props = Get-ItemProperty -Path $SourcePath
+    foreach ($p in $props.PSObject.Properties) {
+        if ($p.Name -notlike "PS*") {
+            Set-ItemProperty -Path $TargetPath -Name $p.Name -Value $p.Value
+        }
+    }
+}
+
+# === DPAPI HEX DECRYPTOR ===
+function Decode-DPAPIHex($hex) {
+    if ([string]::IsNullOrWhiteSpace($hex)) { return $null }
+
+    Add-Type -AssemblyName System.Security
+
+    # Convert hexadecimal → byte array
+    $bytes = for ($i = 0; $i -lt $hex.Length; $i += 2) {
+        [Convert]::ToByte($hex.Substring($i, 2), 16)
+    }
+
+    # Try LocalMachine first
+    try {
+        return [System.Security.Cryptography.ProtectedData]::Unprotect(
+            $bytes, $null,
+            [System.Security.Cryptography.DataProtectionScope]::LocalMachine
+        )
+    }
+    catch {
+        # Try CurrentUser if LocalMachine does not work
+        return [System.Security.Cryptography.ProtectedData]::Unprotect(
+            $bytes, $null,
+            [System.Security.Cryptography.DataProtectionScope]::CurrentUser
+        )
+    }
+}
+
+function TestODBCConnection($DSN) {
+    Write-Host " → Testing ODBC connection..."
+    try {
+        $conn = New-Object System.Data.Odbc.OdbcConnection("DSN=$DSN")
+        $conn.Open()
+        Write-Host " → Connection test: OK" -ForegroundColor Green
+        $conn.Close()
+    } catch {
+        Write-Host " → Connection test: FAILED" -ForegroundColor Red
+        Write-Host $_.Exception.Message
+    }
+}
+$SimbaDSNs = @()
+
+foreach ($root in $DSNRoots) {
+
+    $dsnTablePath = Join-Path $root $DSNListRoot
+    if (!(Test-Path $dsnTablePath)) { continue }
+
+    $dsns = Get-ItemProperty $dsnTablePath
+    foreach ($entry in $dsns.PSObject.Properties) {
+
+        $dsnName = $entry.Name
+        $driverValue = $entry.Value
+
+        if ($driverValue -eq $SimbaDriverName) {
+            $SimbaDSNs += [PSCustomObject]@{
+                Root = $root
+                DsnName = $dsnName
+                DsnTablePath = $dsnTablePath
+            }
+        }
+    }
+}
+
+if ($SimbaDSNs.Count -eq 0) {
+    Write-Host "No Simba DSNs found. Nothing to migrate."
+    exit
+}
+elseif ($SimbaDSNs.Count -eq 1) {
+    $Chosen = $SimbaDSNs[0]
+}
+else {
+    Write-Host "`nMultiple Simba DSNs found:"
+    for ($i=0; $i -lt $SimbaDSNs.Count; $i++) {
+        Write-Host " [$($i+1)] $($SimbaDSNs[$i].DsnName)   ($($SimbaDSNs[$i].Root))"
+    }
+
+    do {
+        $sel = Read-Host "Enter the number of the DSN you want to migrate"
+    } until ($sel -as [int] -and $sel -ge 1 -and $sel -le $SimbaDSNs.Count)
+
+    $Chosen = $SimbaDSNs[$sel - 1]
+}
+
+Write-Host "`nSelected DSN: $($Chosen.DsnName)"
+Write-Host "Location: $($Chosen.Root)`n"
+
+# ===============================================================
+# === Continue the original loop logic ONLY for chosen DSN    ===
+# ===============================================================
+
+$root = $Chosen.Root
+$dsnName = $Chosen.DsnName
+$dsnTablePath = $Chosen.DsnTablePath
+
+Write-Host "`nFound Simba DSN: $dsnName"
+
+# Source DSN registry key
+$srcDSNKey = Join-Path $root $dsnName
+if (!(Test-Path $srcDSNKey)) {
+    Write-Warning "DSN entry exists in table but no registry key: $srcDSNKey"
+    exit
+}
+
+# Determine target DSN values based on mode
+if ($Mode -eq "replace") {
+    $newDSNName = $dsnName
+} else {
+    $newDSNName = "${dsnName}_Google"
+}
+
+Write-Host " → Target DSN: $newDSNName"
+$dstDSNKey = Join-Path $root $newDSNName
+
+# 1. Update ODBC Data Sources table
+Set-ItemProperty -Path $dsnTablePath -Name $newDSNName -Value $GoogleDriverName
+if ($Mode -eq "replace" -and $newDSNName -eq $dsnName) {
+    Set-ItemProperty -Path $dsnTablePath -Name $dsnName -Value $GoogleDriverName
+}
+
+# 2. Copy registry values
+CopyRegistryTree -SourcePath $srcDSNKey -TargetPath $dstDSNKey
+
+# 3. Update Driver DLL
+$googleDriverKey = Get-ChildItem "HKLM:\SOFTWARE\ODBC\ODBCINST.INI" |
+    Where-Object { $_.PSChildName -eq $GoogleDriverName }
+if (!$googleDriverKey) { Write-Warning "Google driver not found in ODBCINST.INI"; exit }
+
+$googleDLL = (Get-ItemProperty $googleDriverKey.PSPath).Driver
+Set-ItemProperty -Path $dstDSNKey -Name "Driver" -Value $googleDLL
+Write-Host " → Set Driver DLL to: $googleDLL"
+
+# 3b. Fix TrustedCerts
+$driverFolder = Split-Path $googleDLL -Parent
+$rootsCert = Join-Path $driverFolder "Assets\roots.pem"
+if (Test-Path $rootsCert) {
+    Set-ItemProperty -Path $dstDSNKey -Name "TrustedCerts" -Value $rootsCert
+    Write-Host " → Updated TrustedCerts to: $rootsCert"
+} else {
+    Write-Warning " → roots.pem not found in $driverFolder\Assets"
+}
+
+# 4. Decrypt KeyFilePath_Enc
+$encKeyPath = (Get-ItemProperty $srcDSNKey -ErrorAction SilentlyContinue).KeyFilePath_Enc
+if ($encKeyPath) {
+
+    Write-Host " → Decrypting KeyFilePath_Enc..."
+
+    $rawBytes = Decode-DPAPIHex $encKeyPath
+    if ($rawBytes) {
+        $plainPath = [System.Text.Encoding]::UTF8.GetString($rawBytes)
+        Write-Host "   → Decrypted KeyFilePath: $plainPath"
+
+            # Write plain KeyFilePath into new DSN
+            Set-ItemProperty -Path $dstDSNKey -Name "KeyFilePath" -Value $plainPath
+        } else {
+            Write-Warning "   → Failed to decrypt KeyFilePath_Enc"
+        }
+    }
+
+        # 5. Test DSN connectivity
+        TestODBCConnection -DSN $newDSNName
+
+Write-Host "`n=== Migration complete ==="
diff --git a/ci/migration/migrate_dsn.sh b/ci/migration/migrate_dsn.sh
new file mode 100644
index 0000000000..7a12a1aedd
--- /dev/null
+++ b/ci/migration/migrate_dsn.sh
@@ -0,0 +1,326 @@
+#!/bin/bash
+#
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Migration script for Linux/MacOS ODBC DSNs
+# - Migrates from "Simba Google BigQuery ODBC Connector"
+# - to       "ODBC Driver for BigQuery"
+
+# Usage:
+#     migrate.sh copy   <installer.zip>
+#     migrate.sh replace <installer.zip>
+
+set -euo pipefail
+
+usage() {
+  cat <<EOF
+Usage: $0 <mode> <installer-path>
+ mode:    copy    - create new DSN(s) named <orig>_google (originals untouched)
+          replace - update existing Simba DSN(s) in-place (name preserved)
+ installer-path: directory OR .zip OR .tar.gz/.tgz
+Environment:
+ ODBCINI - optional path to odbc.ini. If not set, /etc/odbc.ini is used.
+EOF
+  exit 1
+}
+
+if [ $# -ne 2 ]; then
+  usage
+fi
+
+MODE="$1"
+INSTALLER="$2"
+
+if [ "$MODE" != "copy" ] && [ "$MODE" != "replace" ]; then
+  echo "ERROR: mode must be 'copy' or 'replace'"
+  exit 1
+fi
+
+# Resolve odbc.ini location (env first, then /etc/odbc.ini)
+if [ -n "${ODBCINI-}" ]; then
+  ODBCINI_PATH="$ODBCINI"
+elif [ -f "/etc/odbc.ini" ]; then
+  ODBCINI_PATH="/etc/odbc.ini"
+else
+  echo "ERROR: No odbc.ini found. Set ODBCINI env var or ensure /etc/odbc.ini exists."
+  exit 1
+fi
+
+if [ ! -f "$ODBCINI_PATH" ]; then
+  echo "ERROR: odbc.ini not found at resolved path: $ODBCINI_PATH"
+  exit 1
+fi
+
+echo "Using odbc.ini: $ODBCINI_PATH"
+echo "Mode: $MODE"
+echo "Installer input: $INSTALLER"
+
+WORKDIR=""
+CLEANUP=0
+
+# Prepare installer extraction if necessary
+if [ -d "$INSTALLER" ]; then
+  echo "Installer is a directory: $INSTALLER"
+  WORKDIR="$(realpath "$INSTALLER")"
+else
+  WORKDIR="$(mktemp -d)"
+  CLEANUP=1
+  case "$INSTALLER" in
+    *.zip)
+      if ! command -v unzip >/dev/null 2>&1; then
+        echo "ERROR: unzip is required to extract zip archives."
+        exit 1
+      fi
+      unzip -q "$INSTALLER" -d "$WORKDIR"
+      ;;
+    *.tar.gz | *.tgz)
+      tar -xzf "$INSTALLER" -C "$WORKDIR"
+      ;;
+    *)
+      echo "ERROR: Installer must be a directory, .zip, or .tar.gz/.tgz"
+      exit 1
+      ;;
+  esac
+fi
+
+# Find lib/ folder in extracted tree
+LIBDIR=""
+if [ -d "$WORKDIR/lib" ]; then
+  LIBDIR="$WORKDIR/lib"
+else
+  LIBDIR="$(find "$WORKDIR" -type d -name lib | head -n 1 || true)"
+fi
+
+if [ -z "$LIBDIR" ] || [ ! -d "$LIBDIR" ]; then
+  echo "ERROR: Could not find lib/ folder inside installer content."
+  [ "$CLEANUP" -eq 1 ] && rm -rf "$WORKDIR"
+  exit 1
+fi
+
+# Find driver file (prefer .so, else .dylib)
+NEW_DRIVER_SRC="$(find "$LIBDIR" -maxdepth 1 -type f -name "*.so" -print -quit || true)"
+if [ -z "$NEW_DRIVER_SRC" ]; then
+  NEW_DRIVER_SRC="$(find "$LIBDIR" -maxdepth 1 -type f -name "*.dylib" -print-quit || true)"
+fi
+
+if [ -z "$NEW_DRIVER_SRC" ]; then
+  echo "ERROR: No .so or .dylib found in $LIBDIR"
+  [ "$CLEANUP" -eq 1 ] && rm -rf "$WORKDIR"
+  exit 1
+fi
+
+echo "Found driver in installer: $NEW_DRIVER_SRC"
+
+DEST_DIR="/usr/local/lib/google_odbc"
+mkdir -p "$DEST_DIR"
+DRIVER_BASENAME="$(basename "$NEW_DRIVER_SRC")"
+DEST_DRIVER_PATH="$DEST_DIR/$DRIVER_BASENAME"
+
+if [ ! -w "$DEST_DIR" ]; then
+  echo "Copying driver to $DEST_DIR with sudo..."
+  sudo cp -f "$NEW_DRIVER_SRC" "$DEST_DRIVER_PATH"
+  sudo chmod 644 "$DEST_DRIVER_PATH"
+else
+  cp -f "$NEW_DRIVER_SRC" "$DEST_DRIVER_PATH"
+  chmod 644 "$DEST_DRIVER_PATH"
+fi
+
+echo "Driver copied to: $DEST_DRIVER_PATH"
+
+TS="$(date +%Y%m%d%H%M%S)"
+ODBC_BAK="${ODBCINI_PATH}.bak.${TS}"
+cp -a "$ODBCINI_PATH" "$ODBC_BAK"
+echo "Backup of odbc.ini saved to: $ODBC_BAK"
+
+# Detect Simba DSNs in [ODBC Data Sources]
+SIMBA_DSNS=()
+while IFS= read -r line; do
+  trimmed="$(echo "$line" | sed -e 's/^[ \t]*//' -e 's/[ \t]*$//')"
+  if [[ "$trimmed" == *=*Simba\ Google\ BigQuery\ ODBC\ Connector* ]]; then
+    name="${trimmed%%=*}"
+    SIMBA_DSNS+=("$name")
+  fi
+done < <(awk '/^\[ODBC Data Sources\]/{flag=1; next} /^\[/{flag=0} flag{print}' "$ODBCINI_PATH" || true)
+
+echo "Detected Simba DSN(s): ${SIMBA_DSNS[*]}"
+
+##############################################################################
+# ★★★ MINIMAL CHANGE: Ask user which DSN to migrate if multiple exist ★★★
+##############################################################################
+if [ ${#SIMBA_DSNS[@]} -eq 0 ]; then
+  echo "No Simba DSNs found. Exiting."
+  [ "$CLEANUP" -eq 1 ] && rm -rf "$WORKDIR"
+  exit 0
+
+elif [ ${#SIMBA_DSNS[@]} -eq 1 ]; then
+  SELECTED_DSN="${SIMBA_DSNS[0]}"
+
+else
+  echo "Multiple Simba DSNs detected:"
+  i=1
+  for d in "${SIMBA_DSNS[@]}"; do
+    echo "  $i) $d"
+    i=$((i + 1))
+  done
+
+  while true; do
+    read -rp "Select the DSN to migrate: " choice
+    if [[ "$choice" =~ ^[0-9]+$ ]] && [ "$choice" -ge 1 ] && [ "$choice" -le ${#SIMBA_DSNS[@]} ]; then
+      SELECTED_DSN="${SIMBA_DSNS[$((choice - 1))]}"
+      break
+    fi
+    echo "Invalid selection. Try again."
+  done
+fi
+
+echo "Selected DSN: $SELECTED_DSN"
+
+# Override the array so downstream code behaves unchanged
+SIMBA_DSNS=("$SELECTED_DSN")
+##############################################################################
+
+TMP_ODBC="$(mktemp)"
+cp "$ODBCINI_PATH" "$TMP_ODBC"
+
+# Replace driver & description inside a DSN section
+update_dsn_inplace() {
+  target="$1"
+  newdrv="$2"
+  newdesc="$3"
+  awk -v section="$target" -v drv="$newdrv" -v desc="$newdesc" '
+  BEGIN { in_section=0 }
+  {
+    if ($0 ~ ("^\\[" section "\\]$")) { print; in_section=1; next }
+    if ($0 ~ /^\[/ && in_section==1) { in_section=0 }
+    if (in_section==1) {
+      if ($0 ~ /^Description=/) { print "Description=" desc; next }
+      if ($0 ~ /^Driver=/) { print "Driver=" drv; next }
+    }
+    print
+  }
+  ' "$TMP_ODBC" >"${TMP_ODBC}.new" && mv "${TMP_ODBC}.new" "$TMP_ODBC"
+}
+
+create_dsn_copy() {
+  orig="$1"
+  copyname="${orig}_google"
+  newdrv="$2"
+  newdesc="$3"
+
+  if awk -v s="[$copyname]" 'BEGIN{found=0} $0==s{found=1} END{exit !found}' "$TMP_ODBC"; then
+    echo "Note: $copyname already exists; skipping creation."
+    return
+  fi
+
+  awk -v s="[$orig]" 'BEGIN{in=0} {
+    if($0==s){in=1; print; next}
+    if(in==1 && $0~/^\[/){exit}
+    if(in==1) print
+  }' "$TMP_ODBC" >"${TMP_ODBC}.${orig}.section" || true
+
+  if [ ! -s "${TMP_ODBC}.${orig}.section" ]; then
+    echo "Warning: Original section [$orig] not found; creating minimal section for $copyname"
+    {
+      echo "[$copyname]"
+      echo "Description=$newdesc"
+      echo "Driver=$newdrv"
+    } >>"$TMP_ODBC"
+    return
+  fi
+
+  awk -v orig="$orig" -v copy="$copyname" -v drv="$newdrv" -v desc="$newdesc" '
+  NR==1{
+    if($0 ~ ("^\\[" orig "\\]$")){print "[" copy "]"} else {print}
+    next
+  }
+  {
+    if($0 ~ /^Description=/){ print "Description=" desc; next }
+    if($0 ~ /^Driver=/){ print "Driver=" drv; next }
+    print
+  }' "${TMP_ODBC}.${orig}.section" >>"$TMP_ODBC"
+
+  rm -f "${TMP_ODBC}.${orig}.section"
+  echo "Created DSN copy: [$copyname]"
+}
+
+NEW_DESC="ODBC Driver for BigQuery DSN"
+NEW_DRV="$DEST_DRIVER_PATH"
+NEW_DRIVER_NAME="ODBC Driver for BigQuery"
+
+# Update DSNs
+for dsn in "${SIMBA_DSNS[@]}"; do
+  if [ "$MODE" = "replace" ]; then
+    awk -v dsn="$dsn" -v newname="$NEW_DRIVER_NAME" '
+    BEGIN { in_ods=0 }
+    {
+      if ($0 ~ /^\[ODBC Data Sources\]/){ print; in_ods=1; next }
+      if ($0 ~ /^\[/ && $0 !~ /^\[ODBC Data Sources\]/){ in_ods=0 }
+      if(in_ods==1){
+        if($0 ~ ("^"dsn"[ \t]*=")){
+          print dsn "=" newname
+          next
+        }
+      }
+      print
+    }' "$TMP_ODBC" >"${TMP_ODBC}.tmp" && mv "${TMP_ODBC}.tmp" "$TMP_ODBC"
+
+    update_dsn_inplace "$dsn" "$NEW_DRV" "$NEW_DESC"
+    echo "Replaced DSN: [$dsn]"
+
+  else
+    create_dsn_copy "$dsn" "$NEW_DRV" "$NEW_DESC"
+    newdsn="${dsn}_google"
+
+    awk -v original="$dsn" -v addeddsn="$newdsn" -v newname="$NEW_DRIVER_NAME" '
+    BEGIN{ in_ods=0; printed=0 }
+    {
+      if($0 ~ /^\[ODBC Data Sources\]/){ print; in_ods=1; next }
+      if($0 ~ /^\[/ && $0 !~ /^\[ODBC Data Sources\]/){
+        if(in_ods==1 && printed==0){
+          print addeddsn "=" newname
+          printed=1
+        }
+        in_ods=0
+      }
+      if(in_ods==1){ print; next }
+      print
+    }
+    END{
+      if(in_ods==1 && printed==0) print addeddsn "=" newname
+    }
+    ' "$TMP_ODBC" >"${TMP_ODBC}.tmp" && mv "${TMP_ODBC}.tmp" "$TMP_ODBC"
+
+    echo "Created DSN copy: [$newdsn]"
+  fi
+done
+
+# Write output back
+if [ -w "$ODBCINI_PATH" ]; then
+  mv "$TMP_ODBC" "$ODBCINI_PATH"
+else
+  echo "Updating $ODBCINI_PATH with sudo..."
+  sudo mv "$TMP_ODBC" "$ODBCINI_PATH"
+  sudo chown root:root "$ODBCINI_PATH" || true
+  sudo chmod 644 "$ODBCINI_PATH" || true
+fi
+
+echo "Updated odbc.ini successfully: $ODBCINI_PATH"
+echo "Backup retained at: $ODBC_BAK"
+echo "Driver in use: $NEW_DRV"
+echo "Mode finished: $MODE"
+
+[ "$CLEANUP" -eq 1 ] && rm -rf "$WORKDIR"
+
+exit 0