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The function `cagg_watermark` returns the time threshold at which materialized data ends and raw query data begins in a real-time aggregation query (union view). The watermark is simply the completed threshold of the continuous aggregate materializer. However, since the completed threshold will no longer exist with the new continuous aggregates, the watermark function has been changed to return the end of the last bucket in the materialized hypertable. In most cases, the completed threshold is the same as the end of the last materialized bucket. However, there are situations when it is not; for example, when there is a filter in the view query some buckets might not be materialized because no data matched the filter. The completed threshold would move ahead regardless. For instance, if there is only data from "device_2" in the raw hypertable and the aggregate has a filter `device=1`, there will be no buckets materialized although the completed threshold moves forward. Therefore the new watermark function might sometimes return a lower watermark than the old function. A similar situation explains the different output in one of the union view tests.
74 lines
3.5 KiB
PL/PgSQL
74 lines
3.5 KiB
PL/PgSQL
-- This file and its contents are licensed under the Apache License 2.0.
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-- Please see the included NOTICE for copyright information and
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-- LICENSE-APACHE for a copy of the license.
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-- This file contains utilities for time conversion.
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CREATE OR REPLACE FUNCTION _timescaledb_internal.to_unix_microseconds(ts TIMESTAMPTZ) RETURNS BIGINT
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AS '@MODULE_PATHNAME@', 'ts_pg_timestamp_to_unix_microseconds' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
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CREATE OR REPLACE FUNCTION _timescaledb_internal.to_timestamp(unixtime_us BIGINT) RETURNS TIMESTAMPTZ
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AS '@MODULE_PATHNAME@', 'ts_pg_unix_microseconds_to_timestamp' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
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CREATE OR REPLACE FUNCTION _timescaledb_internal.to_timestamp_without_timezone(unixtime_us BIGINT)
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RETURNS TIMESTAMP
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AS '@MODULE_PATHNAME@', 'ts_pg_unix_microseconds_to_timestamp'
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LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
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CREATE OR REPLACE FUNCTION _timescaledb_internal.to_date(unixtime_us BIGINT)
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RETURNS DATE
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AS '@MODULE_PATHNAME@', 'ts_pg_unix_microseconds_to_date'
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LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
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CREATE OR REPLACE FUNCTION _timescaledb_internal.to_interval(unixtime_us BIGINT) RETURNS INTERVAL
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AS '@MODULE_PATHNAME@', 'ts_pg_unix_microseconds_to_interval' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
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-- Time can be represented in a hypertable as an int* (bigint/integer/smallint) or as a timestamp type (
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-- with or without timezones). In metatables and other internal systems all time values are stored as bigint.
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-- Converting from int* columns to internal representation is a cast to bigint.
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-- Converting from timestamps to internal representation is conversion to epoch (in microseconds).
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-- Gets the sql code for representing the literal for the given time value (in the internal representation) as the column_type.
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CREATE OR REPLACE FUNCTION _timescaledb_internal.time_literal_sql(
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time_value BIGINT,
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column_type REGTYPE
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)
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RETURNS text LANGUAGE PLPGSQL STABLE AS
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$BODY$
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DECLARE
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ret text;
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BEGIN
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IF time_value IS NULL THEN
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RETURN format('%L', NULL);
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END IF;
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CASE column_type
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WHEN 'BIGINT'::regtype, 'INTEGER'::regtype, 'SMALLINT'::regtype THEN
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RETURN format('%L', time_value); -- scale determined by user.
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WHEN 'TIMESTAMP'::regtype THEN
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--the time_value for timestamps w/o tz does not depend on local timezones. So perform at UTC.
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RETURN format('TIMESTAMP %1$L', timezone('UTC',_timescaledb_internal.to_timestamp(time_value))); -- microseconds
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WHEN 'TIMESTAMPTZ'::regtype THEN
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-- assume time_value is in microsec
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RETURN format('TIMESTAMPTZ %1$L', _timescaledb_internal.to_timestamp(time_value)); -- microseconds
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WHEN 'DATE'::regtype THEN
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RETURN format('%L', timezone('UTC',_timescaledb_internal.to_timestamp(time_value))::date);
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ELSE
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EXECUTE 'SELECT format(''%L'', $1::' || column_type::text || ')' into ret using time_value;
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RETURN ret;
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END CASE;
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END
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$BODY$;
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CREATE OR REPLACE FUNCTION _timescaledb_internal.interval_to_usec(
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chunk_interval INTERVAL
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)
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RETURNS BIGINT LANGUAGE SQL IMMUTABLE PARALLEL SAFE AS
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$BODY$
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SELECT (int_sec * 1000000)::bigint from extract(epoch from chunk_interval) as int_sec;
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$BODY$;
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CREATE OR REPLACE FUNCTION _timescaledb_internal.time_to_internal(time_val ANYELEMENT)
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RETURNS BIGINT AS '@MODULE_PATHNAME@', 'ts_time_to_internal' LANGUAGE C VOLATILE STRICT;
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CREATE OR REPLACE FUNCTION _timescaledb_internal.cagg_watermark(hypertable_id INTEGER)
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RETURNS INT8 AS '@MODULE_PATHNAME@', 'ts_continuous_agg_watermark' LANGUAGE C STABLE STRICT;
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