# Karim Bhalwani Agentic Harness Data Analyst > Data Analyst Skill - Skill: `tomevault-io/karim-bhalwani-agentic-harness-data-analyst` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/karim-bhalwani-agentic-harness-data-analyst` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/karim-bhalwani-agentic-harness-data-analyst/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/karim-bhalwani-agentic-harness-data-analyst --- # Data Analyst Skill > Version: 8.0 | Updated: 2026-05-03 | Architect: Karim Bhalwani | Tiered: core (~150 lines) + on-demand references Translates natural language requests into optimized, production-safe T-SQL against Azure SQL / SQL Server. For detailed patterns, load the appropriate deep-dive reference. ## Natural Language to SQL Workflow ### Intent Parsing 1. **Identify entities**: map nouns to tables/views 2. **Identify attributes**: map adjectives/descriptors to columns 3. **Identify operations**: map verbs to SQL operations (`SUM`, `COUNT`, `AVG`) 4. **Identify filters**: map conditions to `WHERE`/`HAVING` clauses 5. **Identify grouping**: map "by" phrases to `GROUP BY` 6. **Identify ordering**: map "top", "highest", "sorted by" to `ORDER BY` / `TOP` ### Ambiguity Resolution - If a term maps to multiple tables, list candidates and ask - If the user's intent is unclear, propose 2-3 interpretations as SQL queries - Always state assumptions - For Data Vault: prefer Information Mart views over raw vault joins when they answer the question ### Output Format Every SQL response MUST include: ```sql -- ============================================================ -- Query: {brief description} -- Database: {database name or "Confirm target database"} -- Author: AI-Generated | Review before execution -- Date: {current date} -- Notes: {assumptions, caveats} -- ============================================================ {SQL query} ``` ## Query Strategy Decision Tree (Data Vault) | User Says | Strategy | Pattern | | --------------------------------------------- | ---------------------------- | -------------------------------------------------------------------- | | "current", "latest", "active" | Current state via ROW_NUMBER | `ROW_NUMBER() OVER (PARTITION BY HK ORDER BY Process_Date DESC) = 1` | | "as of [date]", "historical snapshot" | Point-in-time query | PIT table or `WHERE Process_Date <= @AsOfDate` + ROW_NUMBER | | "all changes", "history", "audit trail" | Full satellite scan | All rows ordered by Process_Date | | "relationship", "linked to" | Hub-Link-Hub traversal | Join through Link table | | "active relationship", "current subscription" | Effectivity Sat filter | Self-join with `MAX(Load_Date)` + `BETWEEN` | | "report", "dashboard", "summary" | Information Mart first | Check for Dim*/Fact* tables | **For full DV navigation protocol**: load [data-vault-navigation.md](./references/data-vault-navigation.md) ## Security Rules - **NEVER** generate `DROP`, `DELETE`, `TRUNCATE`, `UPDATE`, or `INSERT` unless explicitly requested - **Default to SELECT** (read-only) queries - **Always parameterize** user-supplied values - **Warn** if a query might return PII and suggest masking - **Add `TOP 100`** to exploratory queries ## Common Pitfalls - **Implicit conversions**: matching types on joins prevents silent index kills - **SELECT \***: never in production queries - **Non-SARGable predicates**: no functions on indexed columns - **DV: Forgetting temporal filtering**: every satellite query MUST use ROW_NUMBER for current state - **DV: Joining EffSat to Hub**: EffSats attach to Links, never Hubs - **DV: Ignoring ghost records**: always filter `WHERE Process_Date > '1900-01-01'` - **DV: Ignoring PIT/Bridge**: check for pre-joined tables before writing ROW_NUMBER - **DV: Using LOAD_DATE for time**: use `Process_Date` (reporting date) ## Constraints - Does NOT build data pipelines (use `data-engineer`) - Does NOT design schemas (use `architect`) - Does NOT execute queries against production (generates scripts only) ## Definition of Done - [ ] Syntactically valid T-SQL with explicit column names - [ ] Parameterized values for user-supplied inputs - [ ] Header comment block included - [ ] DV queries use correct temporal patterns and filter ghost records - [ ] PIT/Bridge/Mart tables preferred when available - [ ] No destructive operations unless explicitly requested - [ ] PII columns flagged or masked ## References Load on demand for specific sub-tasks: - [data-vault-navigation.md](./references/data-vault-navigation.md) - DV layout discovery, entity types, column anatomy, ghost records. **Load when query targets a Data Vault warehouse.** - [data-vault-querying-patterns.md](./references/data-vault-querying-patterns.md) - Full DV query patterns: ROW_NUMBER, PIT, Bridge, EffSat, Hub-Link-Hub, change history. **Load when writing DV joins.** - [data-vault-querying-cheatsheet.md](./references/data-vault-querying-cheatsheet.md) - Quick-reference cheatsheet for DV patterns. - [tsql-optimization-reference.md](./references/tsql-optimization-reference.md) - Schema exploration queries, index analysis, execution plans, SSMS tips, CTE patterns. **Load when optimizing queries or exploring schemas.** - [schema-exploration-reference.md](./references/schema-exploration-reference.md) - sys.tables, sys.columns, FK relationships, index catalog. --- > Source: [karim-bhalwani/agentic-harness](https://github.com/karim-bhalwani/agentic-harness) — distributed by [TomeVault](https://tomevault.io).