Bug Report

1. Minimal reproduce step (Required)

1. Create a table with large TEXT rows (to stress sampling collector memory).
2. Set analyze v2 and limit concurrency to increase chance of cleanup reordering:
   • set @@tidb_analyze_version=2;
   • set @@tidb_build_sampling_stats_concurrency=1;
3. Run:
   • analyze table <tbl> with 1.0 samplerate;

(Optionally) enable internal check/assert to catch the invariant violation:

• build/test with --tags=intest, or
• export GO_FAILPOINTS="/enableInternalCheck=return(true)" (with failpoint-enabled build)

2. What did you expect to see? (Required)

Global analyze memory usage (label: LabelForGlobalAnalyzeMemory, metric: analyze/inuse) should never be negative.

3. What did you see instead (Required)

The in-use value can become temporarily negative during Analyze v2 execution (observed via metrics / internal check).

4. Root cause analysis (Optional)

In AnalyzeColumnsExecV2.subBuildWorker, buffered consume/release are deferred in a way that may apply Release before Consume (because multiple defers execute LIFO),
causing transient negative bytesConsumed for the global analyze memory tracker.

5. Proposed fix (Optional)

• Ensure buffered Consume is applied before buffered Release in worker cleanup.
• Add an internal invariant check for LabelForGlobalAnalyzeMemory.
• Add regression test for Analyze v2 to avoid future regressions.

6. Affected versions (Optional)

master

7. Related PR (Optional)

• executor, util/memory: keep global analyze memory usage non-negative #65503