U147: Partitioning error

Example Postgres Log Output:

ERROR:  partition "measurement_y2026m01" would overlap partition "measurement_y2025m12"
LINE 1: ...ITION OF measurement FOR VALUES FROM ('2025-12-15') TO ('2026...

ERROR:  cannot attach index "idx" as a partition of index "pidx"
DETAIL:  The index definitions do not match.

ERROR:  every hash partition modulus must be a factor of the next larger modulus

ERROR:  unsupported PRIMARY KEY constraint with partition key definition
DETAIL:  PRIMARY KEY constraints cannot be used when partition keys include expressions.

Explanation:

A command that defines or restructures a partitioned table was rejected. This is a single broad classification covering DDL-level partitioning errors, because there are many distinct messages that all point at an invalid partition configuration.

Common cases:

• Bounds that overlap or are invalid. A new range partition covering values an existing partition already claims, an empty range (FROM above TO), a bound with the wrong number of values, or a bound that conflicts with the default partition’s current contents.
• Hash partition modulus/remainder rules. Every modulus must be a factor of the next larger one, and the remainder must be below the modulus.
• Constraints that do not include the partition key. UNIQUE, PRIMARY KEY and EXCLUDE constraints on a partitioned table must include all partitioning columns, since Postgres enforces them per-partition.
• ATTACH/DETACH that cannot be performed. Mismatched column definitions, a partition already pending detach, or an index whose definition does not match the parent’s.
• Features that are not supported on partitioned tables or partitions. Identity columns on partitions, unlogged partitioned tables, ROW triggers with transition tables on partitions, and similar.

Two adjacent situations are classified elsewhere:

• A row that does not route to any partition at runtime, or that fails a partition constraint, is V103: Check constraint violation - it is a data problem, not a definition problem.
• "x" is not a partition of ... and similar wrong-kind-of-object messages are U149: Wrong object type.

Recommended Action:

This generally points to problems in the partition maintenance strategy, which is often an application problem. Check the details of the message and investigate your partition management mechanism.

For partition bounds, remember that range bounds are inclusive at the lower end and exclusive at the upper end, so adjacent partitions should share an endpoint (... TO ('2026-01-01') followed by FROM ('2026-01-01') ...).

Learn More:

• Postgres Documentation: Table Partitioning
• Postgres Documentation: ALTER TABLE … ATTACH PARTITION