sql-executor
Skill1 starsChanged 4 days agoMITView on GitHub
Practitioner guidance for querying, tuning, validating, and troubleshooting enterprise databases (SQL Server, Oracle, PostgreSQL, SQLite, MongoDB, MS Access, MySQL) via the sql-connector MCP server. Covers multi-engine joins, GIN/GiST/BRIN indexing, stored procedures, TVFs, Oracle cursors, CTEs, #temp tables, OLAP cubing, window functions, and cohort analytics. Use when asked to "write a sql join", "optimize sql query", "tune database index", "sql cube", "grouping sets", "sql cohort analysis", "postgres gin index", "oracle cursor", "sql stored procedure", "sql cte", or "run database queries".
1 other project uses a version of this.
Adopted by
Most recently taken up by
- zeroclaw-labs/zeroclaw-skillstheir own version, first seen Sep 24, 2026
Other versions1 project uses a version of this.
Word for word · 0
None found.
Edited · 0
None found.
Wrote their own version · 1
- zeroclaw-labs/zeroclaw-skills★ 65same name
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository32 other files it gives its agents.
- AGENTS.mdAGENTS.md
- agent-orchestratorSkill
- algorithmic-complexity-analyzerSkill
- api-securitySkill
- architectural-planningSkill
- caching-queues-reviewerSkill
- code-reviewerSkill
- csharp-developerSkill
- design-pattern-detectorSkill
- detect-overengineeringSkill
- github-security-scanner-hookSkill
- java-developerSkill
- legacy-code-modernizationSkill
- llm-as-judgeSkill
- load-memorySkill
- nodejs-executorSkill
- playwright-bdd-testerSkill
- powershell-writerSkill
- python-api-writerSkill
- python-developerSkill
- python-linterSkill
- react-developerSkill
- remote-pod-log-analyzerSkill
- save-memorySkill
- scan-halucinated-testsSkill
- scan-repo-readmeSkill
- skill-creatorSkill
- sql-connectorSkill
- sync-github-forksSkill
- trace-code-contextSkill
- troubleshoot-and-fixSkill
- typescript-developerSkill
The file
We split this skill into the rules it gives an agent
3 rules. About 0 are common, 2 are distinctive, and 1 is very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈2
Distinctive · estimate
This author's own choices. Worth a look.
1
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Very specific: line 29
Before generating queries, stored procedures, or table schemas, consult detect-overengineering:
- Distinctive: line 30
Avoid Speculative Indexes: Do not index every column proactively.
- Distinctive: line 31
Avoid Query Ceremony: Prefer simple ANSI joins over multi-level nested CTEs unless intermediate materialization is required.
≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
SQL Executor
Architectural heuristics and execution guidance for querying, indexing, and optimizing enterprise relational and document databases via the sql-connector MCP server.
Architectural Heuristics & Decision Matrix
| Task Category | Recommended Strategy | When NOT to Use | Trade-Offs & Rationale |
| Multi-Table Joins | ANSI-92 joins; CROSS/OUTER APPLY (SQL Server); LATERAL (Postgres) | Legacy Oracle (+); unparenthesized MS Access 3+ joins | ANSI provides portable semantics; APPLY/LATERAL correlate rows without Cartesian bloat. |
| CTEs vs #TempTables | Chained/Recursive CTEs for trees; #TempTable for $> 1,000$ rows | Re-evaluating expensive CTEs multiple times in SQL Server | CTEs inline cleanly; #TempTable provides full column histograms, indexes, and TempDB caching. |
| OLAP & Cubing | GROUP BY GROUPING SETS / ROLLUP | Unbounded CUBE on $> 4$ dimensions ($2^N$ blowup) | GROUPING SETS avoids combinatorial explosion of unnecessary sub-aggregations. |
| Specialized Indexing | GIN for JSONB/trigrams; GiST for ranges; BRIN for append-only logs | B-Trees on high-cardinality JSONB/text or terabyte append-only logs | GIN enables containment/trigram search; BRIN gives 99% space savings on sequential data. |
| Stored Procedures & TVFs | Inline TVFs (iTVFs); parameterized sp_executesql / CALL | Multi-statement TVFs (mTVFs); string concatenation SQL | iTVFs inline into optimizer plans; dynamic SQL with parameters blocks SQL injection. |
| Oracle Cursors | SYS_REFCURSOR for drivers; BULK COLLECT + LIMIT 1000 | Row-by-row (RBAR) loops; BULK COLLECT without LIMIT | Bulk operations eliminate PL/SQL context switches; LIMIT prevents PGA memory exhaustion. |
| Window Functions | ROWS BETWEEN ... framing; DENSE_RANK() for top $N$ per group | Unbounded RANGE BETWEEN when physical rows suffice | ROWS operates on physical offsets avoiding temporary disk spooling. |
🛡️ Over-Engineering Self-Check (Anti-Bloat Guardrail)
Before generating queries, stored procedures, or table schemas, consult detect-overengineering:
- Avoid Speculative Indexes: Do not index every column proactively. Only index proven predicates.
- Avoid Query Ceremony: Prefer simple ANSI joins over multi-level nested CTEs unless intermediate materialization is required.
- Avoid
SELECT *: Explicitly specify required columns to enable Index-Only Scans.
📚 Modular Deep Topics
- MCP Workflow & Schema Discovery — Discovery workflow, tool payloads, and connection handling.
- Multi-Engine Joins Architecture — Dialect-specific join syntax,
APPLY,LATERAL, and MS Access parentheses rules. - Temporary Structures, CTEs & #TempTables — Chained/Recursive CTEs, CTE materialization,
#TempTablevs@TableVariable, and GTTs. - OLAP Cubing & Advanced Analytics — CUBE, ROLLUP, GROUPING SETS, percentiles, sessionization, and cohort retention.
- Window Functions, TVFs & Pivoting — Analytic window functions (
ROWSvsRANGE), cross-engine TVFs, and matrix pivoting. - Indexing & Performance Tuning — B-trees, composite ordering, sargability anti-patterns, and execution plans.
- PostgreSQL Specialized Indexing — GIN (
jsonb_ops,jsonb_path_ops,pg_trgm), GiST, and BRIN time-series indexes. - Stored Procedures, TVFs & Dynamic SQL — iTVFs vs mTVFs, output parameters, and
sp_executesql. - Oracle Cursors & PL/SQL Optimization —
SYS_REFCURSOR,BULK COLLECT+FORALLbatching, and cursor locking. - Data Extraction & Validation — Uniqueness, orphan checks, nullability audits, and checksums.
- Troubleshooting & Firewall Resolution — Resolving firewall blocks, deadlocks, and driver setup.
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