Designated timestamp
QuestDB offers the option to elect a column as a designated timestamp. This allows you to specify which column the tables will be indexed by in order to leverage time-oriented language features and high-performance functionalities.
A designated timestamp is elected by using the
timestamp(columnName)
function:
- during a CREATE TABLE operation
- during a SELECT operation
(
dynamic timestamp
) - when ingesting data via ILP, for tables that do not already exist in QuestDB,
partitions are applied automatically by day by default with a
timestamp
column
info
Checking if tables contain a designated timestamp column can be done via the
tables()
and table_columns()
functions which are described in the
meta functions documentation page.
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Properties- Only a column of type
timestamp
can be elected as a designated timestamp. - Only one column can be elected for a given table.
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Out-of-order policyAs of version 6.0.0, QuestDB supports the ingestion of records that are out-of-order (O3) by time. QuestDB detects and adjusts data ingestion for O3 data automatically and no manual configuration is required.
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AdvantagesElecting a designated timestamp allows you to:
- Partition tables by time range. For more information, see the partitions reference.
- Use time series joins such as
ASOF JOIN
. For more information, see the JOIN reference.