Query Pending Event In Power BI Performance Analyzer

A quick note for anyone like me who spends too much time looking at the JSON exports from Performance Analyzer in Power BI Desktop: you may have noticed an event called Query Pending that isn’t (as yet) documented in the Word doc that explains the format of these JSON files.

It turns out that it’s not that interesting – it’s an event that has been added as part of an effort to make sure there are events to cover the whole of the query lifecycle. After the DAX queries for each visual in your report are generated they are added to a queue before they are executed. In some cases there could be several queries in the queue waiting to be executed, in which case they are said to be “pending”, and the Query Pending event tells you how long a query is in this pending state.

I haven’t seen a duration of longer than a couple of milliseconds for this event though, so you probably don’t need to worry much about it. If you ever do see a long Query Pending event please leave a comment – I’m curious to know what the cause might be.

[Thanks to John Vulner and Jon Ludwig for this information]

4 responses

  1. 80 – 46ms, still just a blink but I have 60 of them for one page. Something like 37 visuals on one page but its what they wanted. Pretty clear why those are piling up. Thanks for the link to the Word Doc, that is super useful and despite being a Webb Acolyte, I somehow missed that.

  2. Hello Chris, I have seen anomaly while connecting to datasets via xmla endpoints using performance analyzer from SSMS. It’s kind of throwing error never able to success on connecting any clues? Thanks.

  3. It seems not so useful and I’m wondering whether it has been implemented the right way.
    In a visual that takes 2 seconds (most of them in the “Others” category), only a few milliseconds are spent in Query Pending.
    The “Query Pending” event is before “Execute Semantic Query”. In reality the largest gap is between “Execute Semantic Query” and “Parse Query Result” of the same “Query” event.
    Perhaps, we need a “Parse Pending” event to fill the gap?

  4. Pingback: Power BI Performance Analyzer Event: Query Pending – Curated SQL

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