What is trino-best-practices?

Guidance for reviewing Trino SQL queries, execution plans, and performance settings with attention to the data connector being used. Trino is a query engine that reads data from systems such as Hive and Iceberg rather than storing it all itself.

Use it to review joins, filters, aggregations, EXPLAIN output, session settings, and Hive or Iceberg workloads while separating Trino behavior from connector-specific behavior.

Generic database advice can be wrong when connector behavior changes how a query runs. This guidance requires examining the query and plan before suggesting an optimization.

trino-best-practices — Skill for Codex by Adelphopoet

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add Adelphopoet/trino-best-practices-skill --skill trino-best-practices

Clone the repo

git clone --depth 1 https://github.com/Adelphopoet/trino-best-practices-skill

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/adelphopoet/trino-best-practices-skill/trino-best-practices/github.svg)](https://agentmods.dev/skills/adelphopoet/trino-best-practices-skill/trino-best-practices)

Your own site

<a href="https://agentmods.dev/skills/adelphopoet/trino-best-practices-skill/trino-best-practices"><img src="https://agentmods.dev/badge/skills/adelphopoet/trino-best-practices-skill/trino-best-practices/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/adelphopoet/trino-best-practices-skill/trino-best-practices"><img src="https://agentmods.dev/badge/skills/adelphopoet/trino-best-practices-skill/trino-best-practices.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,924 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00047	$0.01924
Opus 5	$0.00023	$0.00962
Sonnet 5	$0.00009	$0.00385
Haiku 4.5	$0.00005	$0.00192

Measured 12d ago against content hash 227110d6dfa2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

trino-best-practices scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/trino-best-practices/SKILL.md · 190 lines

How it starts

The opening of the file, as written. The whole thing — 190 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Trino Best Practices

This skill teaches an agent how to review Trino SQL, read Trino execution plans, reason about connector behavior, and troubleshoot slow queries without collapsing into generic SQL advice.

What the skill does

Reviews SQL shape, predicate structure, joins, and aggregation strategy.
Reviews EXPLAIN, EXPLAIN ANALYZE, and EXPLAIN (TYPE IO) output.
Reviews session and catalog choices only after plan evidence exists.
Distinguishes engine behavior from connector behavior.
Covers Hive and Iceberg specifics, plus Lakehouse connector boundary rules.

IMPORTANT: How to apply this skill

Before giving guidance, the agent MUST:

Inspect the query, DDL, plan, or config first. Do not optimize blind.
Identify the catalog, connector, table format, and session properties in play.
Read the relevant rule files from rules/ instead of relying on generic SQL intuition.
Cite rule names in the answer, for example: Per join-choose-distribution....
Prefer Trino- and connector-specific guidance over generic database advice.
State uncertainty explicitly when Trino version, connector behavior, or table design is unclear.
Separate recommendations into the correct layer: SQL shape, table design, file layout, catalog config, or session config.
If a Lakehouse table is DELTA or HUDI, do not pretend this package has full connector-specific coverage; apply the boundary rule, keep advice limited to generic SQL/plan/session evidence, and call out the missing connector-specific context.

Review Procedures

For SQL / query reviews

Read these first:

rules/explain-use-explain-analyze-appropriately.md
rules/plan-explain-read-fragments.md
rules/query-filter-pushdown-preserve-types.md
rules/query-avoid-functions-on-filter-columns.md
rules/query-avoid-select-star.md
rules/query-limit-scan-early.md
rules/query-aggregate-before-join-when-valid.md
rules/join-choose-distribution.md
rules/join-filter-before-join.md
rules/join-watch-row-explosion.md
rules/join-use-semi-join-patterns.md
rules/types-avoid-implicit-mismatch.md
rules/types-varbinary-varchar-awareness.md
rules/anti-pattern-cast-on-join-key.md
rules/anti-pattern-date-wrap-breaks-pruning.md
rules/cte-dont-assume-materialization.md

Read the full file on GitHub · 190 lines

Files

What ships with it

37 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

12d ago First seen · 190 lines · 47 tokens per session scan A 227110d6dfa2

Subscribe to this mod's changes

trino-best-practices is a skill published in the GitHub repository Adelphopoet/trino-best-practices-skill (2 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 47 tokens to every session and 1,924 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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