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email-tracker/external/duckdb/test/optimizer/sampling_pushdown.test
2025-10-24 19:21:19 -05:00

52 lines
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SQL

# name: test/optimizer/sampling_pushdown.test
# description: Test Sampling Pushdown optimization
# group: [optimizer]
statement ok
CREATE TABLE integers1(i INTEGER, j INTEGER)
statement ok
CREATE TABLE integers2(i INTEGER, j INTEGER)
statement ok
INSERT INTO integers1 VALUES (1,1), (2,2), (3, 3), (4,4)
statement ok
INSERT INTO integers2 VALUES (1,1), (2,2), (3, 3), (4,4)
# tablesample system + seq scan becomes sample scan
query II
EXPLAIN SELECT i FROM integers1 tablesample system(0.1%)
----
physical_plan <REGEX>:.*SEQ_SCAN.*System: 0.1%.*
# using sample system + seq scan becomes sample scan
query II
EXPLAIN SELECT i FROM integers1 using sample system(0.1%)
----
physical_plan <REGEX>:.*SEQ_SCAN.*System: 0.1%.*
# tablesample system + seq scan with join becomes sample scan with join
query II
EXPLAIN SELECT * FROM integers1 tablesample system(0.1%), integers2 tablesample system(0.1%)
----
physical_plan <REGEX>:.*SEQ_SCAN.*System: 0.1%.*
# tablesample bernoulli: no pushdown
query II
EXPLAIN SELECT i FROM integers1 tablesample bernoulli(0.1%)
----
physical_plan <REGEX>:.*Bernoulli.*SEQ_SCAN.*
# tablesample reservoir: no pushdown
query II
EXPLAIN SELECT i FROM integers1 tablesample reservoir(0.1%)
----
physical_plan <REGEX>:.*RESERVOIR_SAMPLE.*SEQ_SCAN.*
# tablesample system after a derived table: no pushdown
query II
EXPLAIN SELECT * FROM integers1, integers2 where integers1.i = integers2.i USING SAMPLE SYSTEM(25%)
----
physical_plan <REGEX>:.*System.*SEQ_SCAN.*