# Phase 25–26 — Performance sampling and diagnostics

- Samples the Slow Query Analysis, Connection Statistics, InnoDB Metrics, Dashboard, and Server Status screens on successful refresh.
- `View Trends…` compares current and previous counter values, reporting changes per second when values are monotonic.
- Tracks up to 60 snapshots per open administration screen in memory; `Clear Samples` removes them.
- Slow-query snapshots compare execution counts by Performance Schema SQL digest text.
- No new server privileges, schema modifications, third-party dependencies or external MySQL binaries.

## Limitations
- Samples are not persisted, and are discarded when the screen is closed.
- Slow query analysis is limited to the top 100 digests returned by the existing SQL; digests dropping out of the top 100 will not be comparable.
- For cumulative counters, server restarts or Performance Schema resets can invalidate deltas; negative deltas are suppressed.
- A counter rate is not the same as query latency, and the SQL digest data may be truncated.
- Not compiled with Xcode or tested on a live MySQL server in this environment.