The PDT Reaper
Knowledge DropLast tested: Dec 12, 2019The reaper is the process in Looker that is responsible for dropping no...
Technical Tips & Tricks
Explore technical tips and tricks to help you get the most out of Looker.
Knowledge Base Articles
Dev Mode PDTs
Knowledge DropLast tested: Sep 9, 2019A PDT that has been created/modified in a user's dev mode has the follow...
What is an Instance Slug?
Knowledge DropLast tested: May 1, 2020 It's an identifier for an instance. Instance slug is the combination of...
How to use access filters in derived tables
Knowledge DropLast tested: Oct 31, 2019 QuestionHow do I use access filters inside the SQL of a derived table?...
How to pass a filter condition to a derived table AND keep it in the main query
Knowledge DropLast tested: March 2021The ProblemI need a condition to appear in the WHERE clause of my derived...
How are Out-of-Date PDTs Managed?
Knowledge DropLast tested: May 22, 2018 Persistent Derived Tables are automatically reaped by Looker based on ...
How can I stop or change the order of my PDT builds?
Knowledge DropLast tested: Feb 2021ProblemI have several PDTs building, and I want to either: Pause a PDT from...
Window Functions in Looker
Knowledge DropLast tested: April 2021 How do I use window functions in Looker?Window functions are a very powe...
List of workarounds for sorting pivots by measure / sorting by column totals / dynamic top n ranking
Knowledge DropLast tested: Jul 13, 2018The problemSay you want to see some metrics for your top 10 customers b...
What does the graph_derived_tables_for_model endpoint do?
You can use the graph_derived_tables_for_model endpoint (documentation) to get a dependency graph of all the P...
Does calling ${sql_table_name} in SQL Runner use Dev mode PDTs?
Knowledge DropLast tested: Jan 17, 2019 When you call ${sql_table_name} in SQL Runner, if you're in dev mode, ...
What does "using old version" mean in the PDT panel?
Knowledge DropLast tested: Jan 17, 2019 This is the case where looker is using a previous version of a table a...
Expected \"(\" or keyword SELECT but got keyword WITH at
Knowledge DropLast tested: Jan 17, 2019 This is one example of an error you can get by using a CTE in a derive...
How often are datagroup triggers checked?
Knowledge DropLast tested: Jan 25, 2021 The frequency of datagroup triggers is determined by two things:1. The...
Will selecting "Update" on my License Key affect active LookML code changes or kick off PDTs?
Knowledge DropLast tested: Jun 23, 2017 No. Selecting "Update" on the License Key admin setting will only ping...
What are mode=0 & mode=1 in active_derived_table?
Knowledge DropLast tested: Nov 10, 2020 The mode column indicates the state of the derived table.mode=0 being ...
PDT Logs: Consecutive Trigger Checks
Knowledge DropLast tested: Nov 2, 2020 If you happen to come across consecutive trigger datagroup check's equa...
How do I look up unused PDTs in system activity?
Knowledge DropLast tested: Sep 8, 2020 This link will help navigate you to the pdt_event_log explore (Be sure ...
Can I use a transient schema for PDTs?
Knowledge DropLast tested: Aug 19, 2020 What are transient schemas? https://docs.snowflake.com/en/user-guide/t...
Why can't I query my stable view name?
Knowledge DropLast tested: Mar 23, 2020 You will not be able to query the stable view name until the PDT rebui...
Does a manual rebuild show up in the Admin > PDT panel?
Knowledge DropLast tested: Nov 16, 2017Yep - we report it with the build reason "User Requested Rebuild".This ...
PDT Troubleshooting and use of "Rebuild Derived Tables & Run"
Knowledge DropLast tested: Jul 12, 2017 You might get often faced with questions like:Why is my PDT data wrong...
Can you make a multi-column index for a PDT?
Knowledge DropLast tested; Oct 17, 2017 Right now that's not possible natively.One thing you can do is concat ...
How long does a deleted PDT live on the scratch schema for?
Knowledge DropLast tested: June 2021The PDT reaper process runs at most every hour (while respecting the PDT m...
PDTs showing up 'Not built' in admin panel when they are built
Knowledge DropLast tested: Oct 22, 2018 This can be caused by commented out liquid in a PDT - commenting in Lo...
PDTs - Useful Facts and Troubleshooting PDT Issues
Knowledge DropLast tested: Mar 20, 2017 The BasicsA PDT stands for Persistent Derived Table. It is a Looker-sp...
Can two connections on separate instances share a scratch schema/PDTs? aka Enemy Reaper
Knowledge DropLast tested: May 11, 2020TL/DR: Don't share the schema! Two instances should not share the same ...
Why are my NDT values different when compared to an equivalent explore query?
Knowledge DropLast tested: Sep 6, 2019 One reason why your NDT rows and your corresponding explore query rows ...
persist_for hierarchy
Knowledge DropLast tested: Jan 16, 2019 persist_for can be applied to PDTs, Models and Explores.There is a sig...
Why do I have duplicate PDTs?
Knowledge DropLast tested: Apr 4, 2020 PDTs can be shared by multiple models. When duplicates show up in the A...
