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Informix Error -21540: Compression Operation already in progress on this table/partition

Cause and resolution

Compression Operation already in progress on this table/partition

One of the following operations is already in progress on this partition:

Compress, Uncompress, Repack, Shrink, IPA Update

The current operation must complete before a new one is started.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-21540 fires when a storage-maintenance operation is requested on a table/partition that already has one running — per the official guidance, one of Compress, Uncompress, Repack, Shrink, or IPA Update is already in progress on it.

  1. A Compress, Uncompress, Repack, Shrink, or IPA Update operation already running on the target table/partition, per the official guidance — the direct, only cause.
Solutions / Resolution
  1. Let the current operation complete before starting a new one, per the official guidance.
Examples
N/A

No specific triggering statement is documented beyond overlapping storage-maintenance operations.

Diagnostic Checks
  1. Check whether a Compress/Uncompress/Repack/Shrink/IPA Update operation is already running on the table/partition, and wait for it to finish.
Related Errors / Related Topics
  • -21533 — "Defragment: A defragmentation task is already in progress on this dbspace." An analogous concurrency restriction, for defragmentation rather than compress/repack/shrink operations.

A storage-maintenance operation (Compress/Uncompress/Repack/Shrink/IPA Update) was already running on this table/partition — wait for it to finish before starting another.