An earlier release taught the storage advisor to measure, size and review a table across five engines. This release adds the question that follows a review: given the largest tables and an expected growth, where should they sit? The answer is a plan, with the statements attached.
The plan
- Scope The top tables by size, twenty by default and at most a hundred, with a growth factor from one, today, to a hundred.
- Rules, Informix first Tables out of the root dbspace. A large table's indexes apart from its data. A page size suited to the table. Fragmentation when a partition would pass 80% of its ceiling after growth. A dbspace without room for growth, extended.
- Proposals with statements Each proposal carries the statement to run and the dbspaces to create or extend, sized. A plan reuses only dbspaces the database already uses, and no longer judges a dbspace holding none of the planned tables.
- Pure and tested Two set-based queries feed rules that are tested without a database. Other engines answer
not supportedrather than guessing.
Informix 15
- SMALL and LARGE On Informix 15 a table's format is read from the catalog, not inferred from the version, and every storage tool shows it.
- Conversion over fragmentation A SMALL table that would pass its ceiling is proposed for conversion to LARGE instead of being fragmented.
- Native mode On a native 15 the page-size rule tries 32 KB to 256 KB, and the server's version, default page size and mode are read once per call.
- Proven on a native server Each table states its format, the fill estimate is equal for both formats, a new table is sized LARGE, and the plan runs against it.
Named by the question
- Get, review, estimate, plan The storage tools exposed over MCP are renamed after the question they answer: a table review, a table estimate and a layout plan. Grants follow the renamed tools.
The plan is advice with the statements attached. Nothing runs until a DBA chooses to run it.