GPCC Doesn't Show Graphical Query Plan for History and Running Queries
Article ID: 413729
Updated On:
Products
Issue/Introduction
Users may encounter an issue where the query plan is not visible for certain running or historical queries.
When attempting to view the plan, the message :
this issue can occur inconsistently — for the same query, the plan may be visible during one execution but not in another.
It can be observed that the query ID in the Query Monitor page changes a few seconds after the query starts. Specifically, the last numeric value of the query ID increments by one (for example, 123456789-123456-1 becomes 123456789-123456-2).
When users click on the query ID before this update occurs, the query plan fails to load, leading to the “visual plan unavailable” message.
Environment
Greenplum Command Center (GPCC): 6.14.0
Greenplum Database (GPDB): 6.29.X
Cause
1. Query ID Mismatch
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GPDB internally increments the gp_command_count twice for certain query types.
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This causes the query ID to change mid-execution (e.g., from …-1 to …-2).
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When the user clicks on the initial query ID, GPCC attempts to fetch details for a now-invalid ID, resulting in an unavailable plan view.
2. Missing History Plan Data
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The plan node data for a query is written to the history table only after execution completes.
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In cases where a query is executed within a short-lived session that terminates immediately after completion, the session cleanup process removes temporary data before the plan node information is saved.
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As a result, the history plan is missing, leading to the “visual plan unavailable” message for certain completed queries.
Resolution
A permanent fix will be included in an upcoming GPCC release, addressing both issues.
Temporary Workaround:
- Wait before navigating:
After initiating a query, wait a few seconds on the GPCC UI.
Once the query ID stabilizes (after the update), clicking on the query ID will correctly display the query plan.
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