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Description

This error indicates that a specific constant value has been assigned to more than one partition in a `LIST` partitioned table definition. In MySQL `LIST` partitioning, each value must belong to exactly one partition, ensuring no overlap between partition definitions.

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Error Message

Multiple definition of same constant in list partitioning

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Known Causes

3 known causes

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Overlapping Partition Values

A literal constant value is specified in the `VALUES IN` clause for more than one partition within the same `CREATE TABLE ... PARTITION BY LIST` statement.

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Incorrect List Partition Logic

Misunderstanding that each value used for `LIST` partitioning must be unique across all defined partitions, leading to accidental duplication.

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Copy-Paste Errors

When defining numerous partitions, a common copy-paste mistake can inadvertently duplicate a `VALUES IN` constant from one partition to another.

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Solutions

3 solutions available

1. Identify and Remove Duplicate Partition Constants easy

Manually review and correct the `CREATE TABLE` statement to ensure unique partition values.

1

Locate the `CREATE TABLE` statement that is failing due to the duplicate partition constants. This is usually found in your SQL script or within a database management tool.

2

Examine the `PARTITION BY LIST` clause. Identify the specific column being partitioned and the list of values provided for each partition.

PARTITION BY LIST (column_name) (
    PARTITION p0 VALUES IN (1, 2, 3),
    PARTITION p1 VALUES IN (4, 5, 6),
    PARTITION p2 VALUES IN (1, 7, 8) -- Duplicate '1' found here
);

3

Remove or modify the duplicate constant(s) so that each value appears in only one `VALUES IN` list for the specified column. Ensure that all intended values are covered without overlap.

PARTITION BY LIST (column_name) (
    PARTITION p0 VALUES IN (1, 2, 3),
    PARTITION p1 VALUES IN (4, 5, 6),
    PARTITION p2 VALUES IN (7, 8) -- Corrected: '1' removed from p2
);

4

Re-execute the corrected `CREATE TABLE` statement.

2. Use a Temporary Table for Value Verification medium

Programmatically check for duplicate partition values before creating the table.

1

Create a temporary table to hold the intended partition values. This allows for easy duplicate checking.

CREATE TEMPORARY TABLE temp_partition_values (
    partition_name VARCHAR(64),
    partition_value INT
);

2

Insert all your desired partition values into the temporary table. For example, if you have multiple `VALUES IN` lists, insert each value individually.

INSERT INTO temp_partition_values (partition_name, partition_value)
VALUES
('p0', 1), ('p0', 2), ('p0', 3),
('p1', 4), ('p1', 5), ('p1', 6),
('p2', 1), ('p2', 7), ('p2', 8);

3

Query the temporary table to identify any duplicate `partition_value` entries.

SELECT partition_value, COUNT(*) FROM temp_partition_values GROUP BY partition_value HAVING COUNT(*) > 1;

4

If duplicates are found, review the output of the query above and adjust your insertion logic (or the original partition definitions) to ensure uniqueness. Then, re-insert unique values into the temporary table.

5

Once the temporary table contains only unique values, you can proceed to construct your `CREATE TABLE` statement using these verified values. Finally, drop the temporary table.

DROP TEMPORARY TABLE temp_partition_values;

3. Refactor Partitioning Strategy advanced

Consider alternative partitioning methods if list partitioning is proving too complex to manage without duplicates.

1

Evaluate the data distribution and query patterns for the table. Determine if list partitioning is the most appropriate method.

2

Consider using `PARTITION BY RANGE` if your partitioning column has a sequential or numerical nature. This method partitions data based on ranges of values.

PARTITION BY RANGE (column_name) (
    PARTITION p0 VALUES LESS THAN (100),
    PARTITION p1 VALUES LESS THAN (200),
    PARTITION p2 VALUES LESS THAN MAXVALUE
);

3

Consider using `PARTITION BY HASH` if you want to distribute data evenly across a fixed number of partitions without specific value constraints. This is useful for load balancing.

PARTITION BY HASH (column_name) PARTITIONS 4;

4

If the list of constants is very large and complex, consider if a different data model or a denormalization approach might simplify partitioning. This is a more involved structural change.

5

Implement the chosen alternative partitioning strategy by creating a new table with the desired partitioning scheme or by altering the existing table (if supported and applicable). Be aware that altering existing tables with partitions can be a complex operation.

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Related Errors

5 related errors

MySQL Error 1495: Duplicate Partition Constants