citus/src/test/regress/sql/columnar_memory.sql

103 lines
3.3 KiB
PL/PgSQL

--
-- Testing memory usage of columnar tables.
--
CREATE SCHEMA columnar_memory;
SET search_path TO 'columnar_memory';
CREATE OR REPLACE FUNCTION column_store_memory_stats()
RETURNS TABLE(TopMemoryContext BIGINT,
TopTransactionContext BIGINT,
WriteStateContext BIGINT)
LANGUAGE C STRICT VOLATILE
AS 'citus', $$column_store_memory_stats$$;
CREATE FUNCTION top_memory_context_usage()
RETURNS BIGINT AS $$
SELECT TopMemoryContext FROM column_store_memory_stats();
$$ LANGUAGE SQL VOLATILE;
SET columnar.stripe_row_limit TO 50000;
SET columnar.compression TO 'pglz';
CREATE TABLE t (a int, tag text, memusage bigint) USING columnar;
-- measure memory before doing writes
SELECT TopMemoryContext as top_pre,
WriteStateContext write_pre
FROM column_store_memory_stats() \gset
BEGIN;
SET LOCAL client_min_messages TO DEBUG1;
-- measure memory just before flushing 1st stripe
INSERT INTO t
SELECT i, 'first batch',
-- sample memusage instead of recording everyr row for speed
CASE WHEN i % 100 = 0 THEN top_memory_context_usage() ELSE 0 END
FROM generate_series(1, 49999) i;
SELECT TopMemoryContext as top0,
TopTransactionContext xact0,
WriteStateContext write0
FROM column_store_memory_stats() \gset
-- flush 1st stripe, and measure memory just before flushing 2nd stripe
INSERT INTO t
SELECT i, 'second batch', 0 /* no need to record memusage per row */
FROM generate_series(1, 50000) i;
SELECT TopMemoryContext as top1,
TopTransactionContext xact1,
WriteStateContext write1
FROM column_store_memory_stats() \gset
-- flush 2nd stripe, and measure memory just before flushing 3rd stripe
INSERT INTO t
SELECT i, 'third batch', 0 /* no need to record memusage per row */
FROM generate_series(1, 50000) i;
SELECT TopMemoryContext as top2,
TopTransactionContext xact2,
WriteStateContext write2
FROM column_store_memory_stats() \gset
-- insert a large batch
INSERT INTO t
SELECT i, 'large batch',
-- sample memusage instead of recording everyr row for speed
CASE WHEN i % 100 = 0 THEN top_memory_context_usage() ELSE 0 END
FROM generate_series(1, 100000) i;
COMMIT;
-- measure memory after doing writes
SELECT TopMemoryContext as top_post,
WriteStateContext write_post
FROM column_store_memory_stats() \gset
\x
SELECT (1.0 * :top2/:top1 BETWEEN 0.99 AND 1.01) AS top_growth_ok,
(1.0 * :xact1/:xact0 BETWEEN 0.99 AND 1.01) AND
(1.0 * :xact2/:xact0 BETWEEN 0.99 AND 1.01) AS xact_growth_ok,
(1.0 * :write1/:write0 BETWEEN 0.99 AND 1.01) AND
(1.0 * :write2/:write0 BETWEEN 0.99 AND 1.01) AS write_growth_ok,
:write_pre = 0 AND :write_post = 0 AS write_clear_outside_xact;
-- inserting another bunch of rows should not grow top memory context
INSERT INTO t
SELECT i, 'last batch', 0 /* no need to record memusage per row */
FROM generate_series(1, 50000) i;
SELECT 1.0 * TopMemoryContext / :top_post BETWEEN 0.98 AND 1.02 AS top_growth_ok
FROM column_store_memory_stats();
-- before this change, max mem usage while executing inserts was 28MB and
-- with this change it's less than 8MB.
SELECT
(SELECT max(memusage) < 8 * 1024 * 1024 FROM t WHERE tag='large batch') AS large_batch_ok,
(SELECT max(memusage) < 8 * 1024 * 1024 FROM t WHERE tag='first batch') AS first_batch_ok;
\x
SELECT count(*) FROM t;
SET client_min_messages TO WARNING;
DROP SCHEMA columnar_memory CASCADE;