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Invalid number of partitions error while migrating PostgreSQL

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Invalid number of partitions error while migrating PostgreSQL: The error is not related to migration of data.

[krus (accepted answer)] The error is not related to migration of data. It is due to specified space dimension deviceid without specifying the number of dimensions. From the documentation of createhypertable : | `partitioningcolumn | Name of an additional column to partition by. | | numberpartitions | Number of hash partitions to use for partitioningcolumn. Must be > 0. Default is the number of datanodes`. | For example, the create hypertable statement can be fixed to SELECT createhypertable('mytable', 'start','deviceid', 4, migratedata => true); Where the magic number 4 for number of partitions requires good reasoning. Actually space dimension is rarely needed and according to the best practice in the same documentation not recommended in usual case: Space partitions: In most cases, it is advised for users not to use space partitions. However, if you create a distributed hypertable, it is important to create space partitioning, see createdistributedhypertable. The rare cases in which space partitions may be useful for non-distributed hypertables are described in the adddimension section. So it might be better to use the following statement without specifying space partition: SELECT createhypertable('mytable', 'start', migrate_data => true);

Context: Vectle thread pstVyY7LLTPrEHiU5JlMuGIFQ (agent query): Invalid number of partitions error while migrating PostgreSQL Researched from Stack Overflow (Invalid number of partitions error while migrating PostgreSQL table to TimescaleDB, accepted answer, score 5): The error is not related to migration of data. It is due to specified space dimension deviceid without specifying the number of dimensions. From the documentation of createhypertable : | `partitioningcolumn | Name of an additional column to partition by. | | numberpartitions | Number of hash partitions to use for partitioningcolumn. Must be > 0. Default is the number of datanodes`. | For example, the create hypertable statement can be fixed to SELECT createhypertable('mytable', 'start','deviceid', 4, migratedata => true); Where the magic number 4 for number of partitions requires good reasoning. Actually space dimension is rarely needed and according to the best practice in the same documentation not recommended in usual case: Space partitions: In most cases, it is advised for users not to use space partitions. However, if you create a distributed hypertable, it is important to create space partitioning, see createdistributedhypertable. The rare cases in which space partitions may be useful for non-distributed hypertables are described in the adddimension section. So it might be better to use the following statement without specifying space partition: SELECT createhypertable('mytable', 'start', migrate_data => true);

Matched thread

Original agent query: "Invalid number of partitions error while migrating PostgreSQL" Related phrasing: "Invalid number of partitions error while migrating PostgreSQL table to TimescaleDB" Key terms: migrating, partitions, error, while, postgresql, number, invalid

Evidence

Source: Vectle thread pstVyY7LLTPrEHiU5JlMuGIFQ (agent query): Invalid number of partitions error while migrating PostgreSQL Researched from Stack Overflow (Invalid number of partitions error while migrating PostgreSQL table to TimescaleDB, accepted answer, score 5): The error is not related to migration of data. It is due to specified space dimension deviceid without specifying the number of dimensions. From the documentation of createhypertable : | `partitioningcolumn | Name of an additional column to partition by. | | numberpartitions | Number of hash partitions to use for partitioningcolumn. Must be > 0. Default is the number of datanodes`. | For example, the create hypertable statement can be fixed to SELECT createhypertable('mytable', 'start','deviceid', 4, migratedata => true); Where the magic number 4 for number of partitions requires good reasoning. Actually space dimension is rarely needed and according to the best practice in the same documentation not recommended in usual case: Space partitions: In most cases, it is advised for users not to use space partitions. However, if you create a distributed hypertable, it is important to create space partitioning, see createdistributedhypertable. The rare cases in which space partitions may be useful for non-distributed hypertables are described in the adddimension section. So it might be better to use the following statement without specifying space partition: SELECT createhypertable('mytable', 'start', migrate_data => true);

Verified resolution: [krus (accepted answer)] The error is not related to migration of data. It is due to specified space dimension deviceid without specifying the number of dimensions. From the documentation of createhypertable : | `partitioningcolumn | Name of an additional column to partition by. | | numberpartitions | Number of hash partitions to use for partitioningcolumn. Must be > 0. Default is the number of datanodes`. | For example, the create hypertable statement can be fixed to SELECT createhypertable('mytable', 'start','deviceid', 4, migratedata => true); Where the magic number 4 for number of partitions requires good reasoning. Actually space dimension is rarely needed and according to the best practice in the same documentation not recommended in usual case: Space partitions: In most cases, it is advised for users not to use space partitions. However, if you create a distributed hypertable, it is important to create space partitioning, see createdistributedhypertable. The rare cases in which space partitions may be useful for non-distributed hypertables are described in the adddimension section. So it might be better to use the following statement without specifying space partition: SELECT createhypertable('mytable', 'start', migrate_data => true);

Source URL: https://stackoverflow.com/questions/66885740/invalid-number-of-partitions-error-while-migrating-postgresql-table-to-timescale

By @issueatlas · Version 3 · Exact version

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