SET log_queries = 1; SET max_threads = 1; TRUNCATE system.query_log; -- create table for gin(2) DROP TABLE IF EXISTS simple1; CREATE TABLE simple1(k UInt64,s String,INDEX af (s) TYPE gin(2) GRANULARITY 1) ENGINE = MergeTree() ORDER BY k SETTINGS index_granularity = 2; -- insert test data into table INSERT INTO simple1 VALUES (101, 'Alick a01'), (102, 'Blick a02'), (103, 'Click a03'),(104, 'Dlick a04'),(105, 'Elick a05'),(106, 'Alick a06'),(107, 'Blick a07'),(108, 'Click a08'),(109, 'Dlick a09'),(110, 'Elick b10'),(111, 'Alick b01'),(112, 'Blick b02'),(113, 'Click b03'),(114, 'Dlick b04'),(115, 'Elick b05'),(116, 'Alick b06'),(117, 'Blick b07'),(118, 'Click b08'),(119, 'Dlick b09'),(120, 'Elick b10'); -- check gin index was created SELECT name, type FROM system.data_skipping_indices where (table =='simple1') limit 1; -- search gin index SELECT * FROM simple1 WHERE s LIKE '%01%'; SYSTEM FLUSH LOGS; -- check the query only read 2 granules (4 rows total; each granule has 2 rows) SELECT read_rows, result_rows from system.query_log where query_kind ='Select' and current_database = currentDatabase() and endsWith(trimRight(query), 'SELECT * FROM simple1 WHERE s LIKE \'%01%\';') and result_rows==2 limit 1; -- create table for gin() DROP TABLE IF EXISTS simple2; CREATE TABLE simple2(k UInt64,s String,INDEX af (s) TYPE gin() GRANULARITY 1) ENGINE = MergeTree() ORDER BY k SETTINGS index_granularity = 2; -- insert test data into table INSERT INTO simple2 VALUES (101, 'Alick a01'), (102, 'Blick a02'), (103, 'Click a03'),(104, 'Dlick a04'),(105, 'Elick a05'),(106, 'Alick a06'),(107, 'Blick a07'),(108, 'Click a08'),(109, 'Dlick a09'),(110, 'Elick b10'),(111, 'Alick b01'),(112, 'Blick b02'),(113, 'Click b03'),(114, 'Dlick b04'),(115, 'Elick b05'),(116, 'Alick b06'),(117, 'Blick b07'),(118, 'Click b08'),(119, 'Dlick b09'),(120, 'Elick b10'); -- check gin index was created SELECT name, type FROM system.data_skipping_indices where (table =='simple2') limit 1; -- search gin index SELECT * FROM simple2 WHERE hasToken(s, 'Alick'); SYSTEM FLUSH LOGS; -- check the query only read 4 granules (8 rows total; each granule has 2 rows) SELECT read_rows, result_rows from system.query_log where query_kind ='Select' and current_database = currentDatabase() and endsWith(trimRight(query), 'SELECT * FROM simple2 WHERE hasToken(s, \'Alick\');') and result_rows==4 limit 1; -- create table for gin(2) with two parts DROP TABLE IF EXISTS simple3; CREATE TABLE simple3(k UInt64,s String,INDEX af (s) TYPE gin(2) GRANULARITY 1) ENGINE = MergeTree() ORDER BY k SETTINGS index_granularity = 2; -- insert test data into table INSERT INTO simple3 VALUES (101, 'Alick a01'), (102, 'Blick a02'), (103, 'Click a03'),(104, 'Dlick a04'),(105, 'Elick a05'),(106, 'Alick a06'),(107, 'Blick a07'),(108, 'Click a08'),(109, 'Dlick a09'),(110, 'Elick b10'),(111, 'Alick b01'),(112, 'Blick b02'),(113, 'Click b03'),(114, 'Dlick b04'),(115, 'Elick b05'),(116, 'Alick b06'),(117, 'Blick b07'),(118, 'Click b08'),(119, 'Dlick b09'),(120, 'Elick b10'); INSERT INTO simple3 VALUES (201, 'rick c01'), (202, 'mick c02'),(203, 'nick c03'); -- check gin index was created SELECT name, type FROM system.data_skipping_indices where (table =='simple3') limit 1; -- search gin index SELECT * FROM simple3 WHERE s LIKE '%01%'; SYSTEM FLUSH LOGS; -- check the query only read 3 granules (6 rows total; each granule has 2 rows) SELECT read_rows, result_rows from system.query_log where query_kind ='Select' and current_database = currentDatabase() and endsWith(trimRight(query), 'SELECT * FROM simple3 WHERE s LIKE \'%01%\';') and result_rows==3 limit 1; -- create table for gin(2) for utf8 string test DROP TABLE IF EXISTS simple4; CREATE TABLE simple4(k UInt64,s String,INDEX af (s) TYPE gin(2) GRANULARITY 1) ENGINE = MergeTree() ORDER BY k SETTINGS index_granularity = 2; -- insert test data into table INSERT INTO simple4 VALUES (101, 'Alick 好'),(102, 'clickhouse你好'), (103, 'Click 你'),(104, 'Dlick 你a好'),(105, 'Elick 好好你你'),(106, 'Alick 好a好a你a你'); -- check gin index was created SELECT name, type FROM system.data_skipping_indices where (table =='simple4') limit 1; -- search gin index SELECT * FROM simple4 WHERE s LIKE '%你好%'; SYSTEM FLUSH LOGS; -- check the query only read 1 granule (2 rows total; each granule has 2 rows) SELECT read_rows, result_rows from system.query_log where query_kind ='Select' and current_database = currentDatabase() and endsWith(trimRight(query), 'SELECT * FROM simple4 WHERE s LIKE \'%你好%\';') and result_rows==1 limit 1; -- create table with 1000000 rows DROP TABLE IF EXISTS hextable; CREATE TABLE hextable(k UInt64,s String,INDEX af(s) TYPE gin(0) GRANULARITY 1) Engine=MergeTree ORDER BY (k) SETTINGS index_granularity = 1024 AS SELECT number, format('{},{},{},{}', hex(12345678), hex(87654321), hex(number/17 + 5), hex(13579012)) as s FROM numbers(1000000); -- check gin index was created SELECT name, type FROM system.data_skipping_indices where (table =='hextable') limit 1; -- search gin index select * from hextable where hasToken(s, '2D2D2D2D2D2D1540'); SYSTEM FLUSH LOGS; -- check the query only read 3 granules (6 rows total; each granule has 2 rows) SELECT read_rows, result_rows from system.query_log where query_kind ='Select' and current_database = currentDatabase() and hasToken(query, 'hextable') and result_rows==1 limit 1;