Bug #68548 [Fbk->NoF]: slow calls to mysqli_fetch_field when using MYSQLI_STORE_RESULT_COPY_DATA

Edit report at https://bugs.php.net/bug.php?id=68548&edit=1 ID: 68548 Updated by: php-bugs@lists.php.net Reported by: ryan dot brothers at gmail dot com Summary: slow calls to mysqli_fetch_field when using MYSQLI_STORE_RESULT_COPY_DATA -Status: Feedback +Status: No Feedback Type: Bug Package: MySQLi related Operating System: Linux PHP Version: 5.6.3 Assigned To: cmb Private report: N New Comment: No feedback was provided. The bug is being suspended because we assume that you are no longer experiencing the problem. If this is not the case and you are able to provide the information that was requested earlier, please do so and change the status of the bug back to "Re-Opened". Thank you. Previous Comments: ------------------------------------------------------------------------ [2020-03-09 17:56:52] cmb@php.net The other bug has been fixed, so I wonder whether that resolved this issue as well. ------------------------------------------------------------------------ [2019-02-11 02:32:36] ryan dot brothers at gmail dot com I just submitted bug 77597, where now in PHP 7.3.2, calling mysqli_fetch_field hangs the script completely. ------------------------------------------------------------------------ [2016-05-31 20:38:08] notvalid at gmail dot com Also of note, CPU utilization is maxed out during the delay in returning the list of fields. On a result set with over 1m rows, MYSQLI_STORE_RESULT_COPY_DATA results in over a 30 minute call to fetch_fields() while disabling MYSQLI_STORE_RESULT_COPY_DATA returns data from fetch_fields() almost immediately. ------------------------------------------------------------------------ [2014-12-05 04:15:40] ryan dot brothers at gmail dot com Description: ------------ I am seeing an issue where calls to mysqli_fetch_field() are very slow when using MYSQLI_STORE_RESULT_COPY_DATA. In the below example, the call to fetch_field takes 5 seconds to run. If the below is changed to call store_result() without MYSQLI_STORE_RESULT_COPY_DATA, then the call to fetch_field takes 0.006 seconds to run. Is there a way that the time to call fetch_field could be improved when using MYSQLI_STORE_RESULT_COPY_DATA? I have placed SQL to create a test table of 100,000 rows at https://drive.google.com/uc?export=download&id=0B37DKbJklxg_Y3NadnRjc2tVbE0. Thanks for your help. Test script: --------------- <?php $mysqli = new mysqli('localhost', 'test', 'test', 'test'); $mysqli->real_query("SELECT * FROM a"); $result = $mysqli->store_result(MYSQLI_STORE_RESULT_COPY_DATA); $start = microtime(true); $field = $result->fetch_field(); echo microtime(true) - $start."\n"; exit; Expected result: ---------------- 0.0065169334411621 Actual result: -------------- 5.0267069339752 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=68548&edit=1