Multi-node support is deprecated.

TimescaleDB v2.13 is the last release that includes multi-node support for PostgreSQL versions 13, 14, and 15.

Create a TimescaleDB hypertable distributed across a multinode environment.

create_distributed_hypertable() replaces create_hypertable() (old interface). Distributed tables use the old API. The new generalized create_hypertable API was introduced in TimescaleDB v2.13.

relationREGCLASSIdentifier of the table you want to convert to a hypertable.
time_column_nameTEXTName of the column that contains time values, as well as the primary column to partition by.
partitioning_columnTEXTName of an additional column to partition by.
number_partitionsINTEGERNumber of hash partitions to use for partitioning_column. Must be > 0. Default is the number of data_nodes.
associated_schema_nameTEXTName of the schema for internal hypertable tables. Default is _timescaledb_internal.
associated_table_prefixTEXTPrefix for internal hypertable chunk names. Default is _hyper.
chunk_time_intervalINTERVALInterval in event time that each chunk covers. Must be > 0. Default is 7 days.
create_default_indexesBOOLEANBoolean whether to create default indexes on time/partitioning columns. Default is TRUE.
if_not_existsBOOLEANBoolean whether to print warning if table already converted to hypertable or raise exception. Default is FALSE.
partitioning_funcREGCLASSThe function to use for calculating a value's partition.
migrate_dataBOOLEANSet to TRUE to migrate any existing data from the relation table to chunks in the new hypertable. A non-empty table generates an error without this option. Large tables may take significant time to migrate. Default is FALSE.
time_partitioning_funcREGCLASSFunction to convert incompatible primary time column values to compatible ones. The function must be IMMUTABLE.
replication_factorINTEGERThe number of data nodes to which the same data is written to. This is done by creating chunk copies on this amount of data nodes. Must be >= 1; If not set, the default value is determined by the timescaledb.hypertable_replication_factor_default GUC. Read the best practices before changing the default.
data_nodesARRAYThe set of data nodes used for the distributed hypertable. If not present, defaults to all data nodes known by the access node (the node on which the distributed hypertable is created).
hypertable_idINTEGERID of the hypertable in TimescaleDB.
schema_nameTEXTSchema name of the table converted to hypertable.
table_nameTEXTTable name of the table converted to hypertable.
createdBOOLEANTRUE if the hypertable was created, FALSE when if_not_exists is TRUE and no hypertable was created.

Create a table conditions which is partitioned across data nodes by the 'location' column. Note that the number of space partitions is automatically equal to the number of data nodes assigned to this hypertable (all configured data nodes in this case, as data_nodes is not specified).

SELECT create_distributed_hypertable('conditions', 'time', 'location');

Create a table conditions using a specific set of data nodes.

SELECT create_distributed_hypertable('conditions', 'time', 'location',
data_nodes => '{ "data_node_1", "data_node_2", "data_node_4", "data_node_7" }');
  • Hash partitions: Best practice for distributed hypertables is to enable hash partitions. With hash partitions, incoming data is divided between the data nodes. Without hash partition, all data for each time slice is written to a single data node.

  • Time intervals: Follow the guidelines for chunk_time_interval defined in create_hypertable.

    When you enable hash partitioning, the hypertable is evenly distributed across the data nodes. This means you can set a larger time interval. For example, you ingest 10 GB of data per day shared over five data nodes, each node has 64 GB of memory. If this is the only table being served by these data nodes, use a time interval of 1 week:

    7 days * 10 GB 70
    -------------------- == --- ~= 22% of main memory used for the most recent chunks
    5 data nodes * 64 GB 320

    If you do not enable hash partitioning, use the same chunk_time_interval settings as a non-distributed instance. This is because all incoming data is handled by a single node.

  • Replication factor: replication_factor defines the number of data nodes a newly created chunk is replicated in. For example, when you set replication_factor to 3, each chunk exists on 3 separate data nodes. Rows written to a chunk are inserted into all data notes in a two-phase commit protocol.

    If a data node fails or is removed, no data is lost. Writes succeed on the other data nodes. However, the chunks on the lost data node are now under-replicated. When the failed data node becomes available, rebalance the chunks with a call to copy_chunk.


Found an issue on this page?

Report an issue!