mirror of
https://github.com/GreptimeTeam/greptimedb.git
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discord9
194 lines
8.9 KiB
Plaintext
194 lines
8.9 KiB
Plaintext
-- EVAL OFFSET: fixed UTC epoch phase (offset + k * interval), deterministic.
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CREATE TABLE eval_offset_input (
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ts TIMESTAMP(3) TIME INDEX,
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series STRING,
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v DOUBLE,
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PRIMARY KEY(series)
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);
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Affected Rows: 0
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-- Scheduled at odd seconds (1 + 2k): phase anchored to the Unix epoch.
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CREATE FLOW eval_offset_phase_flow
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SINK TO eval_offset_phase_sink
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EVAL INTERVAL '2s'
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EVAL OFFSET '1s'
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AS
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SELECT date_trunc('second', now()) AS ts, count(v) AS c
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FROM eval_offset_input
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GROUP BY date_trunc('second', now());
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Affected Rows: 0
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-- EVAL INTERVAL without an offset is epoch-anchored: even seconds (2k).
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CREATE FLOW eval_zero_offset_phase_flow
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SINK TO eval_zero_offset_phase_sink
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EVAL INTERVAL '2s'
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AS
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SELECT date_trunc('second', now()) AS ts, count(v) AS c
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FROM eval_offset_input
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GROUP BY date_trunc('second', now());
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Affected Rows: 0
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SHOW CREATE FLOW eval_offset_phase_flow;
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+------------------------+------------------------------------------------------------------------------------------------------------------------+
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| Flow | Create Flow |
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+------------------------+------------------------------------------------------------------------------------------------------------------------+
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| eval_offset_phase_flow | CREATE FLOW IF NOT EXISTS eval_offset_phase_flow |
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| | SINK TO public.eval_offset_phase_sink |
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| | EVAL INTERVAL '2 s' |
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| | EVAL OFFSET '1 s' |
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| | AS SELECT date_trunc('second', now()) AS ts, count(v) AS c FROM eval_offset_input GROUP BY date_trunc('second', now()) |
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+------------------------+------------------------------------------------------------------------------------------------------------------------+
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SELECT flow_definition FROM information_schema.flows WHERE flow_name = 'eval_offset_phase_flow';
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+------------------------------------------------------------------------------------------------------------------------+
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| flow_definition |
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+------------------------------------------------------------------------------------------------------------------------+
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| CREATE FLOW IF NOT EXISTS eval_offset_phase_flow |
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| SINK TO public.eval_offset_phase_sink |
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| EVAL INTERVAL '2 s' |
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| EVAL OFFSET '1 s' |
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| AS SELECT date_trunc('second', now()) AS ts, count(v) AS c FROM eval_offset_input GROUP BY date_trunc('second', now()) |
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+------------------------------------------------------------------------------------------------------------------------+
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-- A zero offset is canonicalized away: SHOW CREATE omits EVAL OFFSET.
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CREATE FLOW eval_zero_offset_canonical_flow
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SINK TO eval_zero_offset_canonical_sink
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EVAL INTERVAL '2s'
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EVAL OFFSET '0s'
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AS
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SELECT date_trunc('second', now()) AS ts, count(v) AS c
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FROM eval_offset_input
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GROUP BY date_trunc('second', now());
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Affected Rows: 0
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SHOW CREATE FLOW eval_zero_offset_canonical_flow;
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+---------------------------------+------------------------------------------------------------------------------------------------------------------------+
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| Flow | Create Flow |
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+---------------------------------+------------------------------------------------------------------------------------------------------------------------+
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| eval_zero_offset_canonical_flow | CREATE FLOW IF NOT EXISTS eval_zero_offset_canonical_flow |
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| | SINK TO public.eval_zero_offset_canonical_sink |
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| | EVAL INTERVAL '2 s' |
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| | AS SELECT date_trunc('second', now()) AS ts, count(v) AS c FROM eval_offset_input GROUP BY date_trunc('second', now()) |
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+---------------------------------+------------------------------------------------------------------------------------------------------------------------+
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SELECT flow_definition FROM information_schema.flows WHERE flow_name = 'eval_zero_offset_canonical_flow';
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+------------------------------------------------------------------------------------------------------------------------+
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| flow_definition |
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+------------------------------------------------------------------------------------------------------------------------+
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| CREATE FLOW IF NOT EXISTS eval_zero_offset_canonical_flow |
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| SINK TO public.eval_zero_offset_canonical_sink |
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| EVAL INTERVAL '2 s' |
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| AS SELECT date_trunc('second', now()) AS ts, count(v) AS c FROM eval_offset_input GROUP BY date_trunc('second', now()) |
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+------------------------------------------------------------------------------------------------------------------------+
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INSERT INTO eval_offset_input VALUES
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(now(), 'a', 1.0),
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(now(), 'b', 2.0);
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Affected Rows: 2
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-- Let both scheduled flows evaluate at least once.
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-- SQLNESS SLEEP 5s
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-- Prove the offset phase: every row the offset flow wrote has an odd
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-- second-of-minute (1 + 2k is always odd), while the zero-offset flow wrote
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-- even seconds (2k is always even). This is deterministic regardless of the
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-- exact wall-clock alignment of the evaluations.
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SELECT
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count(*) > 0 AS offset_flow_ran,
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bool_and(date_part('second', ts)::BIGINT % 2 = 1) AS offset_flow_at_odd_seconds
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FROM eval_offset_phase_sink;
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+-----------------+----------------------------+
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| offset_flow_ran | offset_flow_at_odd_seconds |
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+-----------------+----------------------------+
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| true | true |
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+-----------------+----------------------------+
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SELECT
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count(*) > 0 AS zero_offset_flow_ran,
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bool_and(date_part('second', ts)::BIGINT % 2 = 0) AS zero_offset_flow_at_even_seconds
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FROM eval_zero_offset_phase_sink;
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+----------------------+----------------------------------+
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| zero_offset_flow_ran | zero_offset_flow_at_even_seconds |
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+----------------------+----------------------------------+
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| true | true |
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+----------------------+----------------------------------+
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-- Invalid syntax / validation cases.
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CREATE FLOW invalid_eval_offset_no_interval
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SINK TO invalid_eval_offset_sink
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EVAL OFFSET '1s'
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AS SELECT 1;
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Error: 1004(InvalidArguments), Invalid interval provided: EVAL OFFSET requires EVAL INTERVAL to be specified
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CREATE FLOW invalid_eval_offset_too_large
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SINK TO invalid_eval_offset_sink
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EVAL INTERVAL '1s'
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EVAL OFFSET '2s'
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AS SELECT 1;
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Error: 1004(InvalidArguments), Invalid interval provided: EVAL OFFSET must be in range [0, EVAL INTERVAL), got 2 seconds with EVAL INTERVAL 1 seconds
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CREATE FLOW invalid_eval_offset_fractional
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SINK TO invalid_eval_offset_sink
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EVAL INTERVAL '1s'
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EVAL OFFSET '0.5s'
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AS SELECT 1;
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Error: 1004(InvalidArguments), Invalid interval provided: EVAL OFFSET must be a whole number of seconds
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CREATE FLOW invalid_eval_offset_fractional_interval
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SINK TO invalid_eval_offset_sink
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EVAL INTERVAL '1.5s'
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EVAL OFFSET '1s'
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AS SELECT 1;
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Error: 1004(InvalidArguments), Invalid interval provided: EVAL INTERVAL must be a whole number of seconds when EVAL OFFSET is specified
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CREATE FLOW invalid_eval_offset_month
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SINK TO invalid_eval_offset_sink
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EVAL INTERVAL '1 hour'
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EVAL OFFSET '1 month'
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AS SELECT 1;
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Error: 1004(InvalidArguments), Invalid interval provided: Interval with months is not allowed in EVAL OFFSET
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DROP FLOW eval_offset_phase_flow;
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Affected Rows: 0
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DROP FLOW eval_zero_offset_phase_flow;
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Affected Rows: 0
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DROP FLOW eval_zero_offset_canonical_flow;
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Affected Rows: 0
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DROP TABLE eval_offset_phase_sink;
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Affected Rows: 0
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DROP TABLE eval_zero_offset_phase_sink;
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Affected Rows: 0
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DROP TABLE eval_zero_offset_canonical_sink;
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Affected Rows: 0
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DROP TABLE eval_offset_input;
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Affected Rows: 0
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