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https://github.com/pgvector/pgvector.git
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113 lines
2.5 KiB
Plaintext
113 lines
2.5 KiB
Plaintext
SET enable_seqscan = off;
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-- L2
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CREATE TABLE t (val vector(3));
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INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
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CREATE INDEX ON t USING ivfflat (val vector_l2_ops) WITH (lists = 1);
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INSERT INTO t (val) VALUES ('[1,2,4]');
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SELECT * FROM t ORDER BY val <-> '[3,3,3]';
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val
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---------
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[1,2,3]
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[1,2,4]
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[1,1,1]
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[0,0,0]
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(4 rows)
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SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <-> (SELECT NULL::vector)) t2;
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count
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-------
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4
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(1 row)
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SELECT COUNT(*) FROM t;
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count
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-------
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5
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(1 row)
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TRUNCATE t;
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NOTICE: ivfflat index created with little data
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DETAIL: This will cause low recall.
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HINT: Drop the index until the table has more data.
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SELECT * FROM t ORDER BY val <-> '[3,3,3]';
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val
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-----
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(0 rows)
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DROP TABLE t;
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-- inner product
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CREATE TABLE t (val vector(3));
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INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
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CREATE INDEX ON t USING ivfflat (val vector_ip_ops) WITH (lists = 1);
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INSERT INTO t (val) VALUES ('[1,2,4]');
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SELECT * FROM t ORDER BY val <#> '[3,3,3]';
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val
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---------
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[1,2,4]
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[1,2,3]
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[1,1,1]
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[0,0,0]
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(4 rows)
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SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <#> (SELECT NULL::vector)) t2;
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count
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-------
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4
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(1 row)
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DROP TABLE t;
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-- cosine
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CREATE TABLE t (val vector(3));
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INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
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CREATE INDEX ON t USING ivfflat (val vector_cosine_ops) WITH (lists = 1);
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INSERT INTO t (val) VALUES ('[1,2,4]');
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SELECT * FROM t ORDER BY val <=> '[3,3,3]';
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val
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---------
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[1,1,1]
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[1,2,3]
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[1,2,4]
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(3 rows)
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SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <=> '[0,0,0]') t2;
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count
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-------
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3
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(1 row)
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SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <=> (SELECT NULL::vector)) t2;
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count
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-------
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3
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(1 row)
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DROP TABLE t;
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-- unlogged
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CREATE UNLOGGED TABLE t (val vector(3));
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INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
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CREATE INDEX ON t USING ivfflat (val vector_l2_ops) WITH (lists = 1);
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SELECT * FROM t ORDER BY val <-> '[3,3,3]';
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val
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---------
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[1,2,3]
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[1,1,1]
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[0,0,0]
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(3 rows)
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DROP TABLE t;
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-- options
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CREATE TABLE t (val vector(3));
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CREATE INDEX ON t USING ivfflat (val vector_l2_ops) WITH (lists = 0);
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ERROR: value 0 out of bounds for option "lists"
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DETAIL: Valid values are between "1" and "32768".
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CREATE INDEX ON t USING ivfflat (val vector_l2_ops) WITH (lists = 32769);
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ERROR: value 32769 out of bounds for option "lists"
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DETAIL: Valid values are between "1" and "32768".
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SHOW ivfflat.probes;
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ivfflat.probes
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----------------
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1
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(1 row)
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DROP TABLE t;
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