Getting OOM from large dataset - php

Question

I'm trying to create a spreadsheet (XLSX) from a array containing 60k entries. When it exports, it gives me a spreadsheet with a PHP OOM warning on it nothing else.
$spreadsheet = new Spreadsheet();
$spreadsheet->setActiveSheetIndex(0);
$activeSheet = $spreadsheet->getActiveSheet();
$rowIndex = 2;
foreach ($this->_values as $_val){
$activeSheet->setCellValueByColumnAndRow(1, $rowIndex, trim($_val['item1']));
$activeSheet->setCellValueByColumnAndRow(2, $rowIndex, trim($_val['item2']));
$activeSheet->setCellValueByColumnAndRow(3, $rowIndex, trim($_val['item3']));
$activeSheet->setCellValueByColumnAndRow(4, $rowIndex, trim($_val['item4']));
$activeSheet->setCellValueByColumnAndRow(5, $rowIndex, trim($_val['item5']));
$activeSheet->setCellValueByColumnAndRow(6, $rowIndex, trim($_val['item6']));
$activeSheet->setCellValueByColumnAndRow(7, $rowIndex, trim($_val['item7']));
$activeSheet->setCellValueByColumnAndRow(8, $rowIndex, trim($_val['item8']));
$activeSheet->setCellValueByColumnAndRow(9, $rowIndex, trim($_val['item9']));
$activeSheet->setCellValueByColumnAndRow(10, $rowIndex, trim($_val['item10']));
$activeSheet->setCellValueByColumnAndRow(11, $rowIndex, trim($_val['item11']));
$rowIndex += 1;
}
$spreadsheet->garbageCollect();
$writer = new Xlsx($spreadsheet);
$writer->setPreCalculateFormulas(false);
$writer->setUseDiskCaching(true);
$writer->save("php://temp");
$spreadsheet->disconnectWorksheets();
unset($spreadsheet);

Answer 1

An out of memory error is because your system is, well, out of memory. You can simply increase the amount of memory using something like ini_set('memory_limit', '750M'); assuming your system has the space
Or, if XLSX isn't needed (that is: if you could use a CSV instead, which Excel can still open) you could stream the data to the spreadsheet instead of loading it all into memory at once, then printing. That would look like this:
foreach ($this->_values as $_val){
for($i=1; $i<=11; $i++) {
echo trim($_val['item'.$i]);
if($i<11) echo ",";
}
echo "\n";
}
You could also include the CSV header at the top of the PHP file, so the page would prompt a download instead of showing you the contents of the CSV file. This is the CSV header cal: header("Content-type: text/csv");