Note PMM QAN data sources and prepared-statement visibility#357
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patrickbirch merged 1 commit intoJul 8, 2026
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Add a note in the PMM section clarifying that QAN reads only a file-based slow query log or Performance Schema, and that server-side prepared statements show placeholders and no EXPLAIN under Performance Schema (upstream MySQL behavior). Signed-off-by: Michael Coburn <michael.coburn@percona.com>
patrickbirch
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Jul 8, 2026
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What
Adds a short, expectation-setting note so readers recognize why PMM Query Analytics (QAN) may show incomplete data for MySQL prepared-statement workloads.
Why
Server-side prepared statements (used by most application drivers, e.g. JDBC) are exposed by upstream MySQL to Performance Schema with placeholder parameters (
?) rather than literal values. As a result, QAN query examples appear as placeholders and EXPLAIN is unavailable for them. This is upstream MySQL behavior, not a PMM limitation. The note helps users self-diagnose instead of assuming data is missing.Placed in the PMM section of the cluster monitoring page.
Scope
Documentation only — a single admonition in
docs/monitoring.md. Part of a coordinated set of PRs across pmm-doc, psmysql-docs, pxc-docs, k8sps-docs, and k8spxc-docs.DCO: signed off.