MaxCompute SQL Engine Syntax Skill

Provides MaxCompute SQL engine syntax guidance for text2sql scenarios. MaxCompute is based on Hive SQL extensions and has significant differences from ANSI standard SQL.

Usage

Load corresponding reference files based on question type (can be combined). The load column indicates relative loading weight (heavy ≈ large, medium ≈ moderate), for budget estimation, not exact token counts. Each file's opening paragraph describes its own scope.

| Trigger condition | File | load | |---|---|---| | NL→SELECT generation / text2sql (determine intent, granularity, table-column mapping, output format first) | references/text2sql_principles.md | light | | Generate MaxCompute SELECT queries (dialect rules, DQL default must-read) | references/maxcompute_select_guide.md | heavy | | Match query pattern keywords: Top N / top-N per group / year-over-year / month-over-month / consecutive N days / retention / row-to-column / column-to-row / PIVOT / UNPIVOT / array expansion / LATERAL VIEW / EXPLODE / JSON extraction / GET_JSON_OBJECT / cumulative / running total / Range Join / GROUPING SETS / CUBE / ROLLUP / pagination / paging | references/sql_query_patterns.md | medium | | SQL execution failure requiring diagnosis and recovery (including ODPS-0xxx error codes)| references/sql_common_errors.md | medium |

Relationship: text2sql_principles.md provides engine-independent NL→SELECT generation principles; maxcompute_select_guide.md is the single authoritative source for MaxCompute DQL dialect rules (unsupported syntax/functions/partitioning/types/SET parameters). sql_query_patterns.md provides query template snippets only, without duplicating rules.

Out of Scope

The following scenarios exceed this skill's scope:

• MaxCompute non-SQL interfaces: Tunnel / MapReduce / Graph / PyODPS DataFrame API, SDK invocation methods
• Console and permission management: Quota requests, IAM / RAM roles, project owner operations — use Aliyun console or support tickets
• Execution plan-level deep tuning: Only lists common SET parameters and hints; does not analyze specific plan nodes / Fuxi DAG / data skew formation paths
• Cluster-side / platform-side failures: Worker crashes, resource scheduling failures, MetaStore transaction conflicts, storage layer read/write errors — these are support ticket issues, not SQL issues