Dirk created CALCITE-5258:
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Summary: Support MySQL style index hints
Key: CALCITE-5258
URL: https://issues.apache.org/jira/browse/CALCITE-5258
Project: Calcite
Issue Type: Improvement
Environment: Calcite 1.31.0
Reporter: Dirk
{{MySQL has its own syntax for index hints:
[https://dev.mysql.com/doc/refman/8.0/en/index-hints.html]}}
{{Some examples are :}}
{{SELECT * FROM t1 USE INDEX (i1) IGNORE INDEX FOR ORDER BY (i2) ORDER BY a;}}
{{SELECT * FROM t1 USE INDEX FOR JOIN (i1) FORCE INDEX FOR JOIN (i2);}}
{{This differs from the index hints syntax that Calcite supports and that most
DBMSes support. }}
{{From my tests MySQL does not support the /+ ... */ syntax of hints. when
running queries like this all are successfully executed only 1 has an index
choice effect.}}
{{1) SELECT * FROM mytable USE INDEX(col1_index) WHERE col2= false AND col1=3
AND col3= '1'}}
{{2) SELECT * from mytable /*+ INDEX(col1_index) */ WHERE col2= false AND
col1=3 AND col3= '1'}}
{{3) SELECT /*+ INDEX(col1_index) */ * FROM mytable WHERE col2= false AND
col1=3 AND col3= '1'}}
{{It would be great if this would be supported, because otherwise index hints
cannot be used with MySQL.}}
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