** Changed in: mahara Status: In Progress => Fix Committed -- You received this bug notification because you are a member of Mahara Contributors, which is subscribed to Mahara. Matching subscriptions: Subscription for all Mahara Contributors -- please ask on #mahara-dev or mahara.org forum before editing or unsubscribing it! https://bugs.launchpad.net/bugs/1724603
Title: update_hierarchy_path in artefacts/lib.php hammers sql when copying collections Status in Mahara: Fix Committed Bug description: A teacher asked 40 students to copy a 15 page collection with numerous artefacts on each page, which crippled our mysql server. When testing it, even copying the collection once resulted in the web server timing out and raised the sql load incredibly. The code "update_hierarchy_path" in the artefact/lib.php on line 1423 runs an sql query as below: `$sql = "UPDATE {artefact} SET path = ? || SUBSTR(path, ?) WHERE (path = ? OR path LIKE ? )";` The artefact table in Mahara does not index the `path` column, so whilst updating one artefact is not a major issue, but updating the path column for many artefacts hits the database massively. Indexing the path column (which is 1024 bytes) may not be a good solution long term, but either the query needs to be made more efficient or the column indexed. Mahara version 17.04_STABLE (updated about a month ago) Linux RHEL7 MYSQL 5.6 Browser is current chromium Version 61.0.3163.100 (but that is not relevant) To manage notifications about this bug go to: https://bugs.launchpad.net/mahara/+bug/1724603/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~mahara-contributors Post to : mahara-contributors@lists.launchpad.net Unsubscribe : https://launchpad.net/~mahara-contributors More help : https://help.launchpad.net/ListHelp