Bug #92240 when i recreate full text composite index , i could not less result.
Submitted: 30 Aug 2018 4:01 Modified: 30 Aug 2018 6:39
Reporter: Hasan UCAK Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: FULLTEXT search Severity:S2 (Serious)
Version:5.7, 5.7.23, 8.0.12, 5.6.41 OS:Fedora
Assigned to: CPU Architecture:x86

[30 Aug 2018 4:01] Hasan UCAK
Description:
sample process

i create table for full text search test.

create table test_fts(
  `id` int(11) NOT NULL AUTO_INCREMENT,
  col1 varchar(250),
  col2 text DEFAULT NULL,
  col3 varchar(250),
  FULLTEXT KEY `keyword_full_text` (`col1`,`col2`,`col3`),
  PRIMARY KEY (`id`)) engine=innodb DEFAULT CHARSET=utf8
  
i added data 
  
  insert into test_fts(col1,col2,col3) values('hasan-new','test','hasan uçak')
  
  insert into test_fts(col1,col2,col3) values('hasan-new','','hasan uçak')
  
  insert into test_fts(col1,col2,col3) values('hasan-new11','test','hasan uçak')
  
i exec this sql statement.

SELECT *
FROM test_fts WHERE 
( MATCH (col1,col2,col3) AGAINST ('+\"hasan uçak\"' IN BOOLEAN MODE)  )

1 hasan-new test hasan uçak 
2 hasan-new hasan uçak 
3 hasan-new11 test hasan uçak

no problem

when i recreate full text index 

alter table test_fts drop index keyword_full_text;
alter table test_fts add FULLTEXT INDEX keyword_full_text(`col1`, `col2`, `col3`);

query results are

1 hasan-new test hasan uçak 
3 hasan-new11 test hasan uçak

one row is lost.

when i using null value instead empty string, no problem

when anyone value of columns is empty string in index fields , i could get this row. Mysql can't push columns which after empty string column, value to index data is it?

How to repeat:
allways.
[30 Aug 2018 6:39] Umesh Shastry
Hello Hasan,

Thank you for the report and test case.

regards,
Umesh