# Why does an error occur when selecting sys.innodb\_lock\_waits in PMM? **URL:** \ **Category:** MySQL & MariaDB\ **Tags:** pmm, mysql\ **Created:** [August 28, 2024, 4:57am UTC](https://forums.percona.com/t/why-does-an-error-occur-when-selecting-sys-innodb-lock-waits-in-pmm/32639 "2024-08-28T04:57:09Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![wanskim](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/wanskim/32/17813_2.png) [@wanskim](https://forums.percona.com/u/wanskim)\ **Post date:** [August 28, 2024, 4:57am UTC](https://forums.percona.com/t/why-does-an-error-occur-when-selecting-sys-innodb-lock-waits-in-pmm/32639/1 "2024-08-28T04:57:09Z")
I’m using pmm and when I try to look up sys.innodb\_lock\_waits in the panel edit to look up mysql’s lock holder and waiter information on the dashboard, I get an error saying db query error: query failed - please inspect Grafana server log for details. What could be the reason? I am using AWS RDS and the version is mysql 8.0.32. ![image](https://us1.discourse-cdn.com/flex019/uploads/percona1/original/3X/1/7/177e46d87a23b9328cd8daafbfda9fbdec22b0f8.png) ---
**Author:** ![kedarpercona](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/kedarpercona/32/809_2.png) [@kedarpercona](https://forums.percona.com/u/kedarpercona)\ **Post date:** [August 28, 2024, 5:06am UTC](https://forums.percona.com/t/why-does-an-error-occur-when-selecting-sys-innodb-lock-waits-in-pmm/32639/2 "2024-08-28T05:06:06Z")
Welcome to Percona Community @wanskim, The error occur because PMM isn’t giving you an SQL prompt but graphQL. You cannot execute `select *` to the metric there. Also, it isn’t storing `innodb_lock_waits` “table” unless you explicitly export it in some specific format (I don’t know yet). If you want what you’re querying, execute it against database and not PMM. Thanks, K ---
**Author:** ![wanskim](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/wanskim/32/17813_2.png) [@wanskim](https://forums.percona.com/u/wanskim)\ **Post date:** [August 28, 2024, 5:31am UTC](https://forums.percona.com/t/why-does-an-error-occur-when-selecting-sys-innodb-lock-waits-in-pmm/32639/3 "2024-08-28T05:31:30Z")
thank you for your reply This error occurs when querying a table in the DB through a data source. Other tables do not generate errors, but the above error occurs only when querying sys.innodb\_lock\_waits. Even tables other than that table (information\_schema.innodb\_trx) are searched well. ![image](https://us1.discourse-cdn.com/flex019/uploads/percona1/original/3X/0/5/055ff69fa969f606995d37ead18d985a718009c3.png) ---
**Author:** ![kedarpercona](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/kedarpercona/32/809_2.png) [@kedarpercona](https://forums.percona.com/u/kedarpercona)\ **Post date:** [August 28, 2024, 7:24am UTC](https://forums.percona.com/t/why-does-an-error-occur-when-selecting-sys-innodb-lock-waits-in-pmm/32639/4 "2024-08-28T07:24:25Z")
oh! I see in the screenshot here that you’re using datasource as “mysql-1” a database. Well, the question is do you have sys schema on database? can you run this query directly on database? ---
**Author:** ![wanskim](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/wanskim/32/17813_2.png) [@wanskim](https://forums.percona.com/u/wanskim)\ **Post date:** [August 29, 2024, 4:07am UTC](https://forums.percona.com/t/why-does-an-error-occur-when-selecting-sys-innodb-lock-waits-in-pmm/32639/5 "2024-08-29T04:07:56Z")
Yes, tables from other schemas work fine. ---
**Author:** ![lalit.choudhary](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/lalit.choudhary/32/51_2.png) [@lalit.choudhary](https://forums.percona.com/u/lalit.choudhary)\ **Post date:** [August 29, 2024, 7:16am UTC](https://forums.percona.com/t/why-does-an-error-occur-when-selecting-sys-innodb-lock-waits-in-pmm/32639/6 "2024-08-29T07:16:29Z")
> [@wanskim](#): > > using AWS RDS and the version is mysql 8.0.32. As you mentioned, it’s AWS RDS mysql 8.0.32. It is most likely an issue for pmm rds exporter and AWS RDS mysql version. Please report this as bug here [https://perconadev.atlassian.net](https://perconadev.atlassian.net) You should provide the below details in the report, we will test and try to reproduce the same issue once you report this to [https://perconadev.atlassian.net](https://perconadev.atlassian.net) - AWS RDS MySQL and PMM version - How you are adding RDS instance to PMM monitoring. - Error details/ screenshot with error.