Verified history
This means HyperObserve has not found sufficient first-party evidence for a dated before-and-after event. It does not mean MySQL has never changed. Undated values are kept in the current baseline below instead of being presented as history.
Current monitored baseline
HyperObserve currently monitors 4 scoped observations for MySQL. The baseline covers simultaneous client connections, internal row representation, columns per table, network write timeout. Each value retains its plan, product, endpoint, region, account, or runtime qualifier so a future change can be compared against the correct scope.
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| simultaneous client connectionsThe effective maximum is also constrained by open_files_limit. | 151 default; configurable 1–100,000 | MySQL 8.4 server | OracleAug 22, 2026 |
| internal row representationBLOB and TEXT contents are stored separately, but their pointers and overhead still count. | 65,535 bytes | MySQL 8.4 | OracleAug 22, 2026 |
| columns per tableEffective counts can be lower because row size and hidden generated columns also apply. | 4,096 hard limit; InnoDB limit 1,017 | MySQL 8.4 | OracleAug 22, 2026 |
| network write timeoutnet_write_timeout can be configured from 1 second to one year. | 60 seconds default | MySQL 8.4 | OracleAug 22, 2026 |
Tracked constraints and impact
Engine and configured connection, row, column, packet, and timeout constraints. A change is recorded only when it alters a constraint developers can act on, such as capacity planning, request shaping, model selection, deployment configuration, storage design, retry behavior, or account budgeting.
MySQL max_connections Limit
MySQL max_connections Limit, verified against MySQL's official documentation with scope, implementation impact, caveats, and a direct check.
MySQL Row Size Limit
MySQL Row Size Limit, verified against MySQL's official documentation with scope, implementation impact, caveats, and a direct check.
MySQL Column Count Limit
MySQL Column Count Limit, verified against MySQL's official documentation with scope, implementation impact, caveats, and a direct check.
MySQL Network Timeout Defaults
MySQL Network Timeout Defaults, verified against MySQL's official documentation with scope, implementation impact, caveats, and a direct check.
How a change is verified
- Compare the current first-party statement with the previously stored observation, including the exact plan, model, runtime, endpoint, region, and account scope.
- Separate a true product change from documentation clarification, temporary capacity, configurable account state, or a limit that applies to a different execution path.
- Preserve the old and new values, official source, effective date when disclosed, detection date, and practical impact. If those elements cannot be supported, no historical event is published.
Official sources monitored
These first-party documents support the current MySQL baseline. HyperObserve links directly to them so you can confirm the live wording before making a production decision.
max_connections default, range, and effective limit
Column counts, internal row size, and InnoDB page constraints