version: "1.0.0" name: db-maxcompute-sql description: Generate and review MaxCompute/ODPS SQL with project/schema names, partition scan costs and data-type editions. Read the task reference for partition writes, positional mappings and materialized views.

MaxCompute SQL

Generate MaxCompute SQL from the configured datasource context and metadata. MaxCompute is also known as ODPS; its PyODPS SDK and Hive parser fallback do not make it a general Hive or Spark SQL engine.

Namespaces and identifiers

• MaxCompute has no catalog level. A Datus datasource is bound to one project, so do not generate cross-project access.
• In a two-level project, qualify objects as project.table; there is no schema namespace.
• In a schema-enabled project, qualify objects as project.schema.table. Use the configured or metadata-provided schema, which defaults to default when none is supplied.
• Under the Datus adapter contract, a two-part identifier always means project.table, never schema.table. Use all three parts when a schema-qualified identifier is needed.
• Do not emit USE, USE SCHEMA, or SET odps.namespace.schema to switch context. The connector supplies the project, schema, and namespace hint for each job.
• Preserve metadata-provided names and quote reserved words or special identifiers with backticks.

Queries and scan cost

• Add predicates on relevant partition columns when querying partitioned tables. Do not silently enable odps.sql.allow.fullscan.
• LIMIT restricts returned rows only after the distributed scan; it does not reduce bytes scanned or computing cost.
• By default, a global ORDER BY requires a LIMIT. Include a business-appropriate limit rather than inventing an unbounded sort override.
• Use MaxCompute functions and syntax. Do not borrow a MySQL, PostgreSQL, Spark, or Hive construct unless MaxCompute supports it.

Types and expressions

• Projects can use MaxCompute V1, V2, or Hive-compatible data type editions. Follow metadata and explicit project context instead of assuming an edition.
• Prefer explicit CAST when type coercion is material to correctness; implicit conversion rules differ between editions.
• The adapter's hive parser dialect is a parsing fallback, not evidence that odps.sql.hive.compatible is enabled.

Avoid dialect leaks

Before returning SQL, reject invented catalog, warehouse, cluster, distribution, storage-engine, or transaction syntax. Do not assume primary keys, row-level mutation, or Hive compatibility when the table metadata and project settings do not establish them.

Interpret existing ETL and views

• INSERT INTO appends; INSERT OVERWRITE TABLE replaces the table or static partition. Ordinary views are logical definitions; materialized views store data.
• INSERT mappings are positional. Static partition columns are omitted from SELECT; dynamic partition expressions are last and follow the declaration order. Preserve this mapping when following a stored result's lineage.

Task references

• MaxCompute writes and materialized views: INSERT mappings, partition writes, row mutation and materialized-view definitions.

Read these for the requested operation, including SQL-only authoring. Supplied ETL is evidence; follow the user's task.